Methods and systems for heating and manipulating fluids

ABSTRACT

Systems and methods are provided for heating and manipulating a fluid to heat the fluid, evaporate water from the fluid, concentrate the fluid, separate the fluid into fractions; and/or pasteurize the fluid, comprising a closed-loop heating subsystem coupled to a primary fluid-to-fluid heat exchanger, and one or more fluid manipulation subsystems also coupled to the primary fluid-to-fluid heat exchanger.

CROSS REFERENCE TO RELATED APPLICATIONS

This continuing application is based on, claims priority to, and benefitof the following applications and patents, the entire contents of eachof which are incorporated herein by reference for all purposes:

U.S. Provisional Application No. 61/510,485, filed on Jul. 22, 2011(pending).

U.S. Non-Provisional application Ser. No. 13/467,551, filed on May 9,2012 (pending), which claims priority to U.S. Provisional Application61/510,485, filed on Jul. 22, 2011 (pending) and U.S. ProvisionalApplication 61/484,210, filed on May 9, 2011 (expired); and which is acontinuation-in-part of U.S. Non-Provisional application Ser. No.13/069,363 filed on March 22, 2011 (pending); and a continuation-in-partof U.S. Non-Provisional application Ser. No. 12/638,984, filed onDecember 16, 2009 (pending).

U.S. Non-Provisional application Ser. No. 13/069,363, filed on Mar. 22,2011 (pending), which claims priority to U.S. Provisional Application61/316,362, filed on Mar. 22, 2010 (expired); and which is acontinuation-in-part of U.S. Non-Provisional application Ser. No.12/638,984 filed on Dec. 16, 2009 (pending).

U.S. Non-Provisional application Ser. No. 12/638,984 filed on Dec. 16,2009 (pending), and which is a continuation-in-part of U.S.Non-Provisional application Ser. No. 12/615,331 filed on Nov. 10, 2009(abandoned); a continuation-in-pat application of U.S. Non-Provisionalapplication Ser. No. 11/934,645 filed on Nov. 2, 2007 (abandoned); acontinuation-in-part application of U.S. Non-Provisional applicationSer. No. 11/764,270 filed on Jun. 18, 2007 (abandoned); acontinuation-in-part application of U.S. Non-Provisional applicationSer. No. 11/748,475 filed on May 14, 2007, now U.S. Pat. No. 7,614,367,issued on Nov. 10, 2009; a continuation application of U.S.Non-Provisional application Ser. No. 11/741,570 filed on Apr. 27, 2007(abandoned); and a continuation-in-part application of U.S.Non-Provisional application Ser. No. 11/738,644, filed on Apr. 23, 2007(abandoned); and which claims priority to U.S. Provisional ApplicationSer. No. 61/249,841 filed on Oct. 8, 2009 (expired); U.S. StatesProvisional Application Ser. No. 60/883,178 filed on Jan. 3, 2007(expired); U.S. Provisional Application Ser. No. 60/864,160 filed onNov. 2, 2006 (expired); U.S. Provisional Application Ser. No. 60/800,495filed on May 15, 2006 (expired); U.S. Provisional Application Ser. No.60/795,983 filed on Apr. 28, 2006 (expired); and U.S. ProvisionalApplication Ser. No. 60/749,413, filed on Apr. 24, 2006 (expired).

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO APPENDIX

Not applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The inventions disclosed herein relate generally to systems and theiruse for manipulating fluids, and relate specifically to heating,evaporating, condensing, separating, sterilizing and/or otherwisemanipulating fluids, including, but not limited to, industrial fluidsassociated with the oil and gas industries.

2. Description of the Related Art

Industrial operations, such as, but not limited to, oilfield operations,oftentimes require sources of heat for a variety of purposes, such asheating a fluid, evaporating a component from a fluid, condensing afluid, separating a fluid according to its properties, and/orsterilizing or killing objectionable organisms in a fluid. In the past,industry has looked to both open flame (or direct fired) and flamelesssystems to provide the thermal energy for such systems.

For example, U.S. Pat. No. 7,424,916 B2 entitled “Flameless Hot Oiler”is said to describe “[a] flameless heating system comprising: at leastone engine, each engine including a coolant for removing heat from theengine and each engine producing exhaust; a loading means for loadingthe engine; a heat exchange system, the heat exchange system comprising:a heat exchange fluid; a pump for circulating the heat exchange fluid;at least one heat exchanger for transferring heat from the at least oneengine coolant to the heat exchange fluid; and an exhaust heat exchangerfor transferring heat from the exhaust of the at least one engine to theheat exchange fluid; a batch fluid; and a heat exchanger fortransferring heat from the heat exchange system to the batch fluid,wherein heat is transferred from the engine to the heat exchange system,and from the heat exchange system to the batch fluid.”

U.S. Pat. No. 5,279,262 entitled “Mechanical Liquid VaporizingWaterbrake” is said to describe “[a] water brake which uses mechanicalpower to kinetically heat water to vapor or steam, and use thereof as asteam generator or cooling water conserving dynamometer or motionretarder. In the simplest embodiment, radial impeller vanes (5 b) throwwater against stator vanes (6 e), whence the water rebounds to theimpeller (5). The peripheral rebounding movement continues back andforth. Power dissipates as heat in the water causing the water toincrease in temperature and to vaporize. The vapor, being lower indensity and viscosity than is the water, flows to and out a centraloutlet (9) while the denser water is centrifugally separated from thevapor and retained in the peripheral rebounding motion. Water leaving asvapor is continually replaced through a cooling water inlet (8),allowing continuous operation over wide ranges of speed, torque, powerand steam generation rates, both at steady state and at controlled ratesof change.”

U.S. Pat. No. 4,264,826 entitled “Apparatus For Generating ThermalEnergy And Electrical Energy” is said to describe “[a]n apparatus forgenerating thermal and electrical energy includes an internal combustionengine connected to and adapted to drive a generator for providingelectrical power and a brake for generating thermal energy. In oneembodiment, a heat carrier flows through appropriate conduits forabsorbing heat energy from the brake, from the combustion chamber of theengine, and from the engine exhaust gases and delivers the heat energyto a end-use heat exchanger, for example, a room or space heater. In asecond embodiment, the engine exhaust gas flow is used to drive a gasturbine that, in turn, drives a compressor in a thermal cycle to provideadditional heat transfer capability.”

U.S. Patent Application Publication No. 2006/0185621 A1, published onAug. 24, 2006 and entitled “Flameless Boiler,” is said to describe “[a]flameless boiler comprising generator means for generating heat in fluidcirculated there through by shearing of the fluid; a prime moverdrivingly connected to the generator means for shearing of the fluid; asupply reservoir for the fluid; a first pump for circulating the fluidfrom the supply reservoir to the generator means; and a pressure vesselin fluid communication with the generator means for receiving heatedfluid there from, the pressure vessel having an outlet for drawing steamtherefrom.”

U.S. Patent Application Publication No. 2005/0224223 A1, published onOct. 13, 2005 and entitled “Heating Apparatus for Wells,” is said todescribe “[a]n apparatus for warming objects such as production conduitsat a well site comprises an internal combustion engine driving a wellpump. A heat exchanger shell is connected to an exhaust port of theengine, and has an output port. A circulating pump is driven by theengine, and a heating circuit is connected to the circulating pump suchthat liquid in the heating circuit is pumped from a pump output of thecirculating pump through the heating circuit to a pump intake of thecirculating pump. The heating circuit comprises a heat absorbing portioninside the heat exchanger shell arranged such that heat from the exhaustof the engine is transferred to the liquid therein, and a heatingconduit arranged adjacent to a production conduit or other desiredobject such that heat from the liquid in the heating conduit istransferred to the object.”

The present disclosure is directed to improved systems and methods forheating and/or manipulating a fluid.

BRIEF SUMMARY OF THE INVENTION

As a brief summary of the inventions disclosed herein, and withoutlimitation, I have invented methods and systems for manipulating aheated fluid. My inventions include heating systems or subsystems inwhich a thermal energy source is used to heat a fluid in opened-looparrangement or closed-loop arrangement. The thermal energy source maycomprise a direct fired or open flame boiler, an internal combustionengine driving a rotary heating device, or an internal combustion enginepowering an electric boiler. The heating system may be operated at adesired temperature and may be operated at less than atmosphericpressure, atmospheric pressure or may be pressurized. Various plumbing,pumping and control systems are disclosed for the various heatingsystems taught herein.

As a brief summary of the inventions disclosed herein, and withoutlimitation, my inventions also include methods and systems forevaporating a fluid, such as water. These systems and methods mayutilize any of the heating subsystems disclosed herein as a source ofthermal energy to effect evaporation, and a fluid-to-fluid heatexchanger to transfer heat between the heating systems or subsystem andthe evaporation subsystem. The evaporation systems may comprise a flashtank for separating the fluid into its vapor and liquid phases and acondensing heat exchanger for condensing the vapor to liquid. Single andmultiple effect evaporation systems are disclosed. Various plumbing,pumping, measuring and control systems are disclosed for the variousevaporation systems and subsystems taught herein.

As a brief summary of the inventions disclosed herein, and withoutlimitation, my inventions also include methods and systems forconcentrating a fluid. These systems and methods may utilize any of theheating systems or subsystems disclosed herein as a source of thermalenergy to effect concentration, and a fluid-to-fluid heat exchanger totransfer heat between the heating subsystem and the concentrationsubsystem. The concentration systems may comprise a flash tank forseparating the fluid into its vapor and liquid phases and a condensingheat exchanger for condensing the vapor to liquid. Extraction systemsare disclosed for removing concentrated liquid from the flash tank.Various plumbing, pumping, measuring and control systems are disclosedfor the various concentrating systems or subsystems taught herein.

As a brief summary of the inventions disclosed herein, and withoutlimitation, my inventions also include methods and systems forseparating a fluid into its fractional or property-based components.These systems and methods may utilize any of the heating systems orsubsystems disclosed herein as a source of thermal energy to effectconcentration, and a fluid-to-fluid heat exchanger to transfer heatbetween the heating subsystem and the separating subsystem. Theseparating systems may comprise a separation tower for separating thefluid into its fractional components and a condensing heat exchanger forcondensing fluid vapors. Various plumbing, pumping, measuring andcontrol systems are disclosed for the various separating systems andsubsystems taught herein

As a brief summary of the inventions disclosed herein, and withoutlimitation, my inventions also include methods and systems forpasteurizing a fluid. These systems and methods may utilize any of theheating systems or subsystems disclosed herein as a source of thermalenergy to effect pasteurization, and a fluid-to-fluid heat exchanger totransfer heat between the heating subsystem and the pasteurizingsubsystem. The pasteurizing systems may comprise a flash tank forseparating the fluid into its vapor and liquid phases and a condensingheat exchanger for condensing the vapor to liquid. Extraction systemsare disclosed for removing pasteurized liquid from the flash tank.Various plumbing, pumping, measuring and control systems are disclosedfor the various pasteurizing systems or subsystems taught herein.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The Figures described below are provided as an aid to understanding thewritten descriptions provided herein of my inventions. Neither theFigures nor the written descriptions thereof are intended to limit thescope of the appended claims. Rather, the Figures and writtendescriptions are provided to illustrate the inventive concepts to aperson of skill in the art and to enable such person to make and use theinventive concepts.

FIG. 1 illustrates an opened-loop fluid heating system utilizing arotary heating device.

FIG. 2 illustrates a closed-loop fluid heating utilizing a rotaryheating device.

FIG. 3 illustrates another embodiment of a closed-loop fluid heatingsystem utilizing a rotary heating device.

FIG. 4 illustrates yet another embodiment of a closed-loop fluid heatingsystem utilizing a rotary heating device.

FIG. 5 illustrates still another embodiment of a closed-loop fluidheating system utilizing a rotary heating device

FIG. 6A illustrates a closed-loop fluid heating system utilizing adirect-fired boiler.

FIG. 6B illustrates a closed-loop fluid heating system utilizing aDiesel genset.

FIG. 7 illustrates an opened-loop fluid evaporating system utilizing arotary heating device.

FIG. 8 illustrates another embodiment of a fluid evaporating subsystem.

FIG. 9 illustrates a closed-loop fluid evaporating system utilizing arotary heating device.

FIG. 10 illustrates another embodiment of a closed-loop fluidevaporating system utilizing a rotary heating device.

FIG. 11 illustrates yet another embodiment of a closed-loop fluidevaporating system utilizing a rotary heating device.

FIG. 12A illustrates a closed-loop fluid evaporating system utilizing adirect-fired boiler.

FIG. 12B illustrates a closed-loop, multiple effect fluid evaporatingsystem utilizing a direct-fired boiler.

FIG. 12C illustrates a closed-loop, multiple effect fluid evaporatingsystem utilizing a direct-fired boiler.

FIG. 13A illustrates a fluid concentrating subsystem.

FIG. 13B illustrates a direct-fired fluid concentrating system.

FIG. 14 illustrates a closed-loop fluid concentrating system adapted foruse on an offshore rig.

FIG. 15 illustrates another embodiment of a closed-loop fluidconcentrating system utilizing a rotary heating device.

FIG. 16 illustrates yet another embodiment of a fluid concentratingsystem.

FIG. 17 illustrates an embodiment of a fluid separating or fractionatingsystem.

FIG. 18 illustrates another embodiment of a fluid separating orfractionating system

FIG. 19A illustrates one of many embodiments of a pasteurizing systemfor an industrial fluid.

FIG. 19B illustrates another embodiment of a pasteurizing system for anindustrial fluid utilizing a direct-fired boiler.

FIGS. 20A and 20B illustrate one of many embodiments of a fluid heatingand pumping system comprising an electric boiler and diesel genset.

FIGS. 21A and 21B illustrate an embodiment of a system incorporatingmultiple subsystems incorporating the present inventions.

DETAILED DESCRIPTION

One or more illustrative embodiments incorporating the inventionsdisclosed herein are presented below. For the sake of clarity, not allfeatures of an actual implementation are described or shown. Persons ofskill appreciate that in the development of an actual embodimentincorporating aspects of the present inventions, numerousimplementation-specific decisions must be made to achieve thedeveloper's goals, such as compliance with system-related,business-related, government-related and other constraints, which varyby implementation and from time to time. While a developer's effortsmight be complex and time-consuming, such efforts would be,nevertheless, a normal undertaking for those of ordinary skill in theart having benefit of this disclosure.

In general terms, I have invented various systems and methods forheating and/or otherwise manipulating a fluid. Embodiments of my fluidheating systems may comprise opened-loop system or a closed-loop systemin which the By “opened loop,” I mean that the fluid that is desired tobe manipulated is the fluid that flows through the primary heatingdevices. By “closed loop,” I mean that the fluid that is desired to bemanipulated flows through a heat exchanger to pick up heat from anotherfluid that that flows through the primary heating devices in closed looparrangement. The opened loop and closed loop systems described andillustrated herein can batch systems or continuous systems.

One embodiment of my fluid heating and manipulating inventions is aopened-loop system in which the fluid to be heated flows along aplurality of heat paths. For example, one heat path may comprise arotary heating device coupled to a rotary kinetic energy generator, suchas, but not limited to, an internal combustion engine, an externalcombustion engine or an electric motor. The fluid may be heated in therotary heating device and delivered to a reservoir or accumulator. Asecond heat path may comprise a fluid-to-fluid heat exchanger configuredto transfer heat from the engine's water jacket to the fluid. A thirdheat path may comprise and air-to-fluid heat exchanger configured totransfer heat from the engine's exhaust to the fluid. All three pathsmay be combined to produce heated fluid. It will be appreciated thatpumps and valving can be used to control the temperature of the fluid.

Another embodiment of my fluid heating inventions is a closed-loopsystem having a first fluid-to-fluid (such as liquid-to-liquid) heatexchanger that divides the heating system into a primary fluid sectionand a secondary fluid section. The primary fluid section may comprise aprimary energy source, such as a rotary kinetic energy generator,preferable a diesel engine. The rotary kinetic energy is used toenergize a rotary heating device. Regardless of the primary energysource, a primary or working fluid, such as, but not limited to, wateror a water-based mixture, is circulated through the primary energysource to thereby heat the working fluid. In addition, all or a portionof the thermal energy from the primary energy source may be transferredto the fluid as well by one or more heat exchangers. A secondary, orworked, fluid may be passed through the first heat exchanger to transferenergy from the working fluid to the worked fluid, thereby heating theworked fluid.

Any variety of rotary heating devices may be used for embodiments of theinventions disclosed herein. For example, a rotary heating device maycomprise any of a number of known devices, such as, but not limited to,a water brake, a dynamometer, a cavitation heater (such as thosedisclosed in U.S. Pat. No. 7,201,225), and a shear plate or frictionheater. It is preferred that the rotary heating device for theclosed-loops systems disclosed herein an instrumented water brake (e.g.,a dynamometer), such as, but not limited to, Model TD3100 available fromTaylor Dynamometer.

Yet another embodiment of my fluid heating inventions is a closed-loopsystem having a direct-fired boiler, such as a natural gas heater, asthe primary energy source. Fluid heated in the boiler flows through aprimary heat exchanger, such as a fluid-to-fluid heat exchanger totransfer heat to the fluid to be heated, i.e., the worked fluid. Fluidleaving the primary heat exchanger may be accumulated in a reservoirprior to being re-heated in the boiler. Alternately, electrical energymay be supplied by a Diesel-Electric generator set, which is used toheat the fluid in an electric resistance heater or boiler.

Turning now to more specific embodiments of my inventions, FIG. 1illustrates a flameless fluid heating system 100. The system 100illustrated in FIG. 1 directly heats the fluid of interest, i.e., theworked fluid. In other words, this is an “opened-loop” design in whichthe fluid to be heated, such as, for example, fracturing fluid, ispassed directly through the rotary heating device 104. In thisembodiment, the rotary generator 102 is a diesel engine of, for example,750 hp and the rotary heater is a Taylor Dynamometer model TD3100. Fluidenters the system 100 at inlet 120, preferably through an appropriatelysized centrifugal pump 122, and is allowed to flow through threesubstantially parallel heating paths. Adjustment of fluid flow amongthese paths and, therefore, fluid temperature may be controlled by flowcontrol devices or valves 124 a, 124 b and 124 c.

A first path is through valve 124 a to the rotary heater 104 wheretorque from the engine 102 heats the fluid. The fluid leaves the rotaryheater 104 and is collected in a tank 110 that is vented 112 toatmosphere. A main circulation pump 108 draws heated fluid from the tank110 and returns it to system 100, generally. The tank 110 may have afluid level control 111 adapted to control a flow valve 118 to regulatethe level of fluid inside the tank 110.

A second fluid heating path has a portion of the fluid passing throughrestriction 124 b and into a fluid-to-fluid heat exchanger 114 adaptedto transfer heat from the diesel engine 102, such as from the waterjacket coolant, to the worked fluid. Fluid heated in exchanger 114 iscombined with fluid from the rotary heater 104 as illustrated in FIG. 1A third fluid heating path has a portion of the fluid passing throughvalve 124 c and an air-to-fluid heat exchanger 116, such as a finnedtube heat exchanger, adapted to transfer heat from the engine exhaust160 to the fluid. Heated fluid exiting the heat exchanger 116 iscombined with heated fluids from the rotary heater 104 and heatexchanger 114, with the combined heated fluid exiting the system 100 atoutlet 126. The system illustrated in FIG. 1 was designed to raise thetemperature of water by about 38° F. at a flow rate of about 280 gallonsper minute.

Turning now to FIG. 2, disclosed is one of many possible embodiments ofa closed-loop fluid heating system 200. The heating system 200 maycomprise a rotary kinetic energy generator 202, a rotary heating device204 and a primary heat exchanger 206 all plumbed in closed-loop fluidcommunication.

The rotary kinetic energy generator 202 may comprise any of a number ofrotary prime movers, such as, but not limited to electric, pneumatic orhydraulic motors, and internal or external combustion engines. It ispreferred that rotary generator 202 be a conventional diesel or naturalgas engine, such as, for example, a 750 hp diesel engine. It will beappreciated that the amount of horsepower generated by the prime mover202 will control the amount of heat generated by the system 200.

The rotary heating device 204 is preferably a water brake, and mostpreferably a water brake dynamometer, such as Model TD3100 availablefrom Taylor Dynamometer.

The output shaft 203 of the rotary generator 202 may be coupled to therotary heater 204 in known fashion. For example, flex joints or othercoupling mechanisms (not shown) may be used as needed to couple therotary generator 202 to the rotary heater 204. One benefit of using awater brake dynamometer as the rotary heating device is that it may bedirectly coupled to the flywheel or output shaft of an internalcombustion engine.

The outlet side of the rotary heater 204 may be coupled to a reservoiror tank 210. Based on the operating characteristics of the rotary heater204, the tank 210 may be pressurized, evacuated or un-pressurized. Forthe present embodiment using a water brake dynamometer as the rotaryheater 204, it is preferred that tank 210 be un-pressurized and vented212 to atmosphere, thereby operating at atmospheric conditions. A fluidcirculation pump 208, such as a centrifugal pump, is adapted tocirculate or pump the fluid, i.e. the working fluid, through the system200.

Working fluid may be circulated from the tank 210 to a fluid-to-fluidheat exchanger 214 adapted to transfer heat from the rotary generator202 to the working fluid to further heat the fluid. For example, FIG. 2illustrates that the engine coolant 205 from, e.g., the engine's waterjacket, is used to further heat the working fluid. It will beappreciated that heat exchanger 214 may be in addition to or in lieu ofthe engine's conventional air-to-fluid radiator. The working fluid thatexits the heat exchanger 214 may pass through another heat exchanger216, such as an air-to-fluid heat exchanger, to transfer energy from theengine's exhaust gases to the working fluid. As a matter of systemdesign left to those of skill in the art, the engine's exhaust may passentirely through the heat exchanger 216, or may be apportioned such oneportion passes through the heat exchanger 216 and the remainder passesthrough a conventional muffler or exhaust system (not shown).

It will be appreciated that while FIG. 2 illustrates the water jacketheat exchanger 214 downstream from the exhaust gases heat exchanger 216,such orientation is not required and may be reversed or eliminated. Itis preferred; however, that any supplement heat exchangers, such as heatexchangers 214 and 216 be located between the discharge side of therotary heater 204 and the primary heat exchanger 206. Heated workingfluid is circulated from supplemental heat exchangers 214 and/or 216 toprimary heat exchanger 206 and from there back to the rotary heatingdevice 204 to complete the closed loop.

A controllable valve or other flow restriction device 218 may be locatedon the inlet side of the rotary heating device 204 In the embodimentshown in FIG. 2, the valve 218 is controlled by the water brakecontroller (not shown) as a function of engine 202 torque. Thus, valve218 is controlled to load the rotary heater 204 such that the engineoperates near its peak torque.

Also shown in FIG. 2 is bypass circuit 219, which may be used to controlthe temperature of the fluid exiting the rotary heating device 204. Itwill be appreciated that depending on the type of rotary heating device204 used, a backpressure valve (not shown) between the rotary heater 204and the tank 210 may be used to maintain appropriate pressure on therotary heater 204.

It will be appreciated that heating system 200 may be used to heatfluids of all types by flowing such fluid (the “worked” fluid) throughprimary heat exchanger 206 as illustrated in FIG. 2. System 200 may beinstrumented as desired, and as illustrated in FIG. 2, severaltemperature transducers, T, may be beneficial. For example, monitoringthe temperature T1 of the working fluid prior to entry into tank 210 isuseful especially where the tank is vented 212 to atmosphere. Keepingthe temperature of the working fluid below its atmospheric boiling pointwill prevent loss of the working fluid to the atmosphere. It may bedesired to monitor the temperature T4 of the working fluid as it entersthe rotary heater 204 and/or prior to its entry T3 into the primary heatexchanger 206. It will be appreciated that working fluid temperature T3can be controlled in several ways, including adjusting the flow rate ofthe worked fluid through heat exchanger 206, and/or adjusting the torquegenerated by the rotary generator 202, and/or adjusting the flow orworking fluid into the rotary heating device. Controllable bypass loops(not shown) can also be established for each heating source, such asrotary heater 204 and heat exchangers 214 and 216. It will beappreciated that the system 200 can be used to heat a fluid, i.e., the“worked fluid” by passing the worked fluid through fluid-to-fluid heatexchanger 206. A flow control device 250, such as a valve or a pump, canbe used to control the temperature, T2, of the worked fluid.

Moving on to FIG. 3, another embodiment comprising a flameless heatingsystem 300 is illustrated. The fluid heating system 300 may comprise arotary kinetic energy generator 302, a rotary heating device 304 and aprimary heat exchanger 306 all plumbed in closed-loop fluidcommunication. The fluid to be heated, or worked fluid 322, is passedthrough the primary heat exchanger 306 to transfer heat from the workingfluid 301 to the worked fluid 322.

It is preferred that rotary generator 302 be a conventional diesel ornatural gas engine, such as, for example, a 600 hp diesel engine andthat the rotary heating device 304 be a water brake dynamometer, suchas, but not limited to, Model TD3100 available from Taylor Dynamometer.

The output shaft 303 of the rotary generator 302 may be coupled to therotary heater 304 in known fashion. For example, flex joints or othercoupling mechanisms (not shown) may be used as needed to couple therotary generator 302 to the rotary heater 304. One benefit of using awater brake dynamometer as the rotary heating device 304 is that it maybe directly coupled to the flywheel or output shaft of an internalcombustion engine.

The outlet side of the rotary heater 304 may be coupled to a reservoiror tank 310. Based on the operating characteristics of the rotary heater304, the tank 310 may be pressurized, evacuated or un-pressurized. Forthe embodiment of FIG. 3 using a water brake dynamometer as the rotaryheater 304, it is presently preferred that tank 310 be un-pressurizedand vented 312 to atmosphere, thereby operating at atmosphericconditions. A fluid circulation pump 308, such as a centrifugal pump,may be adapted to circulate or pump the fluid, i.e. the working fluid,through the system 300.

The working fluid 301 may pass through a heat exchanger 316, such as anair-to-fluid heat exchanger, to transfer energy from the engine'sexhaust gases 317 to the working fluid 301. As a matter of system designleft to those of skill in the art, the engine's exhaust 317 may passentirely through the heat exchanger 316, or may be apportioned such oneportion passes through the heat exchanger 316 and the remainder passesthrough a conventional muffler or exhaust system (not shown). It ispreferred that exhaust gas heat exchanger 316, and any additional orsupplement heat exchangers, be located between the discharge side of therotary heater 304 and the primary heat exchanger 306. Heated workingfluid 301 is circulated from heat exchangers 316 to primary heatexchanger 306 and from there back to the rotary heating device 304 tocomplete the closed working fluid heating loop.

A controllable valve or other flow restriction device 318 may be locatedon the inlet side of the rotary heating device 304 In the embodimentshown in FIG. 3, the valve 318 is controlled by the water brakecontroller (not shown) as a function of engine 302 torque. Thus, valve318 is controlled to load the rotary heater 304 such that the engineoperates near it peak torque or peak efficiency. Also shown in FIG. 3 isbypass circuit 320, which may be used to control the temperature of theworking fluid 301 exiting the rotary heating device 304. It will beappreciated that depending on the type of rotary heating device 304used, a backpressure valve (not shown) between the rotary heater 304 andthe tank 310 may be used to maintain appropriate pressure on the rotaryheater 304.

It will be appreciated that most, if not all, internal combustionengines suitable for use with the embodiment described in FIG. 3 will besupercharged by either an exhaust gas supercharger (i.e., turbocharger)or a mechanical supercharger. In either instance, the pressurized air isheated by the supercharger to typically undesirable levels, whichtemperature adversely affects the power that the engine 302 cangenerate. To recover some of that waste heat and/or to increase theefficiency of the engine, either the worked fluid 322 or the workingfluid 301 may be used to cool the supercharged air. In a preferredembodiment of the system 300 illustrated in FIG. 3, an air-to-fluid heatexchanger 332 may be inserted into the working fluid 301 discharge linebetween the primary heat exchanger 306 and the rotary heating device 304to transfer heat from the supercharged air to the working fluid 301.

Also shown in FIG. 3 is an optional electrical generator 324 coupled tothe engine 302. For example and not limitation, the generator 324 may bea 50 kilowatt AC generator producing 480 volt, 3 phase power for use inpowering and controlling the various pumps and instruments associatedwith system 300.

Alternately, the rotary heating device 304 may be replaced with anelectrically heated boiler or tank (not shown). In such embodiment, theengine 302 would drive the electrical generator 324 or other electricalgenerator to provide the electrical energy for at least the electricallyheated tank. In all other material respects, such alternate embodimentcould be fashioned similarly to the embodiment shown in FIG. 3. Thus, inthis alternate embodiment, the working fluid could be heated by at leastthe electrically heated tank (not shown) and the engine exhaust 317.

It will be appreciated that the fluid heating system 300 may be used toheat fluids of all types by flowing such fluid 322 (the “worked” fluid)through primary heat exchanger 306 as illustrated in FIG. 3.

In contrast to the system 200 shown in FIG. 2, system 300 of FIG. 3 isdesigned to use the waste heat from the engine's 302 water jacket topreheat the worked fluid 322. As shown in FIG. 3, a worked fluid preheatheat exchanger 326 may be used to transfer heat from the engine coolant328 to the worked fluid 322 before it enters the primary heat exchanger306. It will appreciated that heat exchanger 326 may be in addition toor in lieu of the engine's conventional air-to-fluid radiator heatexchanger. It is preferred a temperature controlled valve (not shown) beused to control the volume or flow rate of engine coolant delivered toheat exchanger 326 so that the engine 302 is not overcooled. Workedfluid pump 330 maybe located before or after preheater 326, butpreferably before. Although not shown in FIG. 3, it will be appreciatedthat valves, controllable valves, instruments or transducers can belocated adjacent the worked fluid inlet or outlet of the primary heatexchanger 306 to monitor or control the properties and characteristicsof heated worked fluid 322.

System 300 may be instrumented as desired, and as illustrated in FIG. 3,several temperature transducers, T, may be beneficial. For example,monitoring the temperature T1 of the working fluid 301 prior to entryinto tank 310 is useful especially where the tank is vented 312 toatmosphere. Keeping the temperature of the working fluid 301 below itsatmospheric boiling point will prevent loss of the working fluid to theatmosphere. It may be desired to monitor the temperature T4 of theworking fluid 301 as it enters the rotary heater 304 (or prior to chargeair heat exchanger 332) and/or prior to its entry T3 into the primaryheat exchanger 306. It will be appreciated that working fluidtemperature T3 can be controlled in several ways, including adjustingthe flow rate of the worked fluid through heat exchanger 306, and/oradjusting the torque generated by the rotary generator 302, and/oradjusting the flow of working fluid into the rotary heating device 304.Controllable bypass loops (not shown) can also be established for eachheating source, such as rotary heater 304 and heat exchanger 316. Itwill be appreciated that the system 300 can be used to heat a fluid 322,i.e., the “worked fluid” by passing the worked fluid throughfluid-to-fluid heat exchanger 306. A flow control device 330, such as avalve or a pump, can be used to control the temperature, T2, of theworked fluid.

In FIG. 4, another embodiment of a flameless fluid heating system 400 isillustrated. The fluid heating system 400 may comprise a closed-loopheat transfer subsystem shown by a dashed line 403. The closed-loop heattransfer system 403 of FIG. 4 comprises a diesel engine 402, which ispreferably a 600 horsepower, Tier III, turbocharged, diesel engine; arotary heating device 404, which is preferably a Model TD3100 availablefrom Taylor Dynamometer; a working fluid tank 410; an engine exhaust gasheat exchanger 416; and a primary fluid-to-fluid heat exchanger 406, allplumbed in closed-loop fluid communication.

The water brake 404 is directly coupled to the flywheel or output shaftof the diesel engine 402. The inlet of the water brake 404 is coupled toa controllable valve 418 to control the amount of closed-loop fluid,i.e., working fluid 401, allowed into the water brake 404 at any giventime. The water brake 404 heats the working fluid 401 therein anddischarges the heated working fluid to the tank 410. For the embodimentof FIG. 4, the tank 410 is un-pressurized and vented 412 to atmosphere,thereby operating at atmospheric conditions.

Working fluid 401, which is preferably a glycol and water mixture, isdrawn from the tank 410 by pump 408 and the working fluid that is thatis not passed through valve 418 to the water brake 404 is directed toexhaust gas heat exchanger 416 where it is further heated by the engineexhaust gas 417. Heated working fluid 401 is then pumped from theexhaust gas heat exchanger 416 into the primary heat exchanger 406,which is preferably a frame-and-plate, fluid-to-fluid heat exchanger.

Also shown in FIG. 4 is an optional electrical generator 424 coupled tothe engine 402. In the embodiment illustrated in FIG. 4, the generator424 is a 50 kilowatt AC generator producing 480 volt, 3 phase power foruse in powering and controlling the various pumps and instrumentsassociated with system 400. FIG. 4 also shows conventional engineradiator 434.

Having now described the heat transfer system 403 illustrated in FIG. 4,it will be appreciated that the system 403 may be run continuously toprovide thermal energy in the working fluid 403 that can be used to heatanother fluid passing through the other portion of primary heatexchanger 406.

To accomplish this heating of a another fluid, i.e., the worked fluid422, system 400 also comprises an open system 436 comprising an inletpump 430 and an engine jacket heat exchanger 426 fluidly coupled to theprimary heat exchanger 406. The discharge side of the primary heatexchanger 406 comprises instrumentation 438, such as but not limited to,temperature transducers, flow rate transducers, mass flow ratetransducers and others; controllable valves 440, manual valves 442 anddischarge pumps 444, as desired or required for a particular purpose.

Because the diesel engine 402 preferred for use in this embodimentdescribed in FIG. 4 is air supercharged, the embodiment of FIG. 4includes a charge air heat exchanger 432 positioned upstream of theengine jacket coolant heat exchanger 426. In this configuration, therelatively cool fluid-to-be-heated 422 cools the charge air before it isintroduced into the engine's combustion chambers, thereby preheating theworked fluid 422. Alternately, as described with respect to FIG. 3, thecharge air heat exchanger 432 may be located in the heat transfer system403 and preferably between the discharge of the primary heat exchanger406 and the tank 410.

It will now be appreciated that heating system 400 may be used to heatfluids, i.e., a worked fluid 422, of all types by flowing such fluid 422through primary heat exchanger 406 as illustrated in FIG. 4. System 400may be instrumented as desired, and as illustrated in FIG. 4, severaltemperature transducers, T, may be beneficial. For example, monitoringthe temperature T1 of the worked fluid 422 prior to entry into chargeair heat exchanger 432 and temperature, T2, of the worked fluid 422exiting the system 400. It will be appreciated that worked fluidtemperature T2 can be controlled in several ways, including adjustingthe flow rate of the worked fluid through heat exchanger 406, and/oradjusting the torque generated by the engine 402, and/or adjusting theflow of working fluid into the water brake 404.

FIG. 5 illustrates another embodiment of a fluid heating system 500using aspects of my inventions. The system 500 comprises a plurality ofclosed-loop heating circuits arranged sequentially to heat a workedfluid 502. The fluid to be heated 502 is pumped into the system 500 by avariable speed pump 504, such as those offered by Viking. The speedcontrol allows the residence time of the fluid 502 within the system 500to be controlled, thereby controlling the final temperature, T4, of thefluid 502. Indeed, in a preferred embodiment, temperature transducer T4controls the pump 504.

The fluid 502 is pumped through one side/portion of a fluid-to-fluidheat exchanger 506. In FIG. 5, heat exchanger 506 is configured totransfer heat from an internal combustion engine's (not shown) waterjacket (working fluid #1) to the fluid 502. As shown, this firstclosed-loop heating circuit may also include an auxiliary air-to-fluidheat exchanger 508 (or radiator) to ensure that the engine has adequatecooling, and may include an after cooler heat exchanger 510 to coolsupercharged or pressurized intake air for the engine.

Fluid 502 heated by this first closed-loop section to temperature T2 ispumped to a second fluid-to-fluid heat exchanger 512. Heat exchanger 512is configured to transfer heat from another fluid (working fluid #2)heated by a rotary heating device 514, such as a water brake, to thefluid 502. The water brake 514, preferably a TD3100 Taylor dynamometer,is driven by an internal combustion engine (not shown), such as a 700 hpdiesel engine. The working fluid heated by the water brake is pumped 516to an atmospheric reservoir or accumulator 518. Controllable valve 520controls the volume of working fluid entering the water brake 514 and,therefore, the temperature T6. After passing through heat exchanger 512,the worked fluid 502 is heated to temperature T3.

Fluid 502 heated by the first and second closed-loop sections totemperature T3 is pumped to a third fluid-to-fluid heat exchanger 522.Heat exchanger 522 is configured to transfer heat from yet another fluid(working fluid #3) heated by an engine exhaust heat exchanger 524, suchas a finned tube air-to-fluid heat exchanger, to the fluid 502. It willbe appreciated that the exhaust gasses from any internal combustion orexternal combustion engine may be used by heat exchanger 524 to heat theworking fluid. In FIG. 5, exhaust gasses from the engine that drivesrotary heating device 514 and exhaust gasses from a 75 kW electricalgenerator, which provides electricity for operating an controlling thepumps, valves and other equipment associated with system 500, are usedto heat the working fluid.

The working fluid heated by the exhaust heat exchanger 524 is pumped 526to the third fluid-to-fluid heat exchanger 522 to raise the temperatureof the worked fluid 502 to its final temperature, T4. Working fluidexits the heat exchanger 522 and flows into an atmospheric reservoir oraccumulator 528. Controllable valve 530 controls the residence time ofthe working fluid in the heat exchanger 522 and, therefore, thetemperature T7.

While the system 500 illustrated in FIG. 5 is a sequential or serialheating system, it will be appreciated that the plurality of closed-loopheating circuits can be arranged in parallel similar to the opened-loopsystem disclosed in FIG. 1.

It is contemplated that an embodiment of the system 500 illustrated inFIG. 5 may consume 5,000,000 Btu/Hr (35 gallons diesel/hr) and transferapproximately 4,500,000 Btu/hr to the worked fluid 502. The system 500may raise the temperature of 60 F water to 140 F at a rate of 2.7Bbl/min or 3.1 hours for 500 Bbl, and the temperature of oil at 60 F to210 F at 3.3 Bbl/min.

Turning now to FIG. 6A, a direct-fired fluid heating system 600 isdisclosed. The heating system 600 comprises a direct-fired fluid heater602, which is preferably a 5,000,000 BTU/hr natural gas water heater,such as, for example, a Parker Boiler Model 6200. It is contemplatedthat the heater 602 would be fired with waste gas from the field meteredinto the heater 602 through pressure control valve 604. Therefore, it isdesirable that the heater 602 burner controls (not shown) allow forsubstantially real-time gas-to-air adjustments to account for changinggas quality. The working fluid in the closed-loop heating circuit ispreferably a 50/50 mixture of water and glycol. The heater 602 heats theworking fluid to temperature T1, which may be, for example, 210 F. Theheated working fluid is pumped 606 through a fluid-to-fluid heatexchanger 608 to transfer heat from the working fluid to the workedfluid 610. Working fluid exits the heat exchanger 608 and enters anatmospheric reservoir or accumulator 612. Pump 606 draws working fluidout of the reservoir 612 and feeds it back to heater 602. A temperaturetransducer T1 cooperates with controllable valve 604 to control thetemperature of the working fluid. In the system illustrated in FIG. 6,the worked fluid may be heated to about 170 F.

FIG. 6B illustrates an alternative heating system 600 utlilizing aDiesel genset, 603 to power an electric boiler 604. The heating system600 comprises a Diesel engine 602 and electrical generator 624, whichtogether may be considered “genset” 603 and an electrical boiler 604.The genset 603 generates electricity, such as three-phase alternatingcurrent power, which is fed to the electric boiler 604 by suitable powercables 625. The working fluid in the closed-loop heating system ispreferably a 50/50 mixture of water and glycol. The boiler 604 heats theworking fluid to temperature T1, which may be, for example, 210° F. Theheated working fluid is pumped 608 through a fluid-to-fluid heatexchanger 618 to transfer heat from the working fluid to the workedfluid 622. Working fluid exits the heat exchanger 618 and returns toboiler 604. An reservoir or accumulator 610 may be utilized as needed,and may be located before or after the boiler 604. FIG. 6B shows anatmospheric reservoir 610 located downstream of boiler 604. Atemperature transducer T1 cooperates with controllable valves to controlthe temperature of the working fluid. In the system illustrated in FIG.6B, the worked fluid may be heated to about 170 F.

Also shown in system 600 of FIG. 6B is an exhaust gas heat exchanger 616configured to transfer waste heat from the engine's 602 exhaust to theworking fluid. As illustrated in FIG. 6B, the exhaust gas heat exchanger616 may be located downstream of the boiler 604 and upstream of theprimary heat exchanger 618. It will be appreciated that other sources ofwaste heat may be captured to heat the working fluid. For example as istaught herein with respect to other embodiments of my inventions, awater jacket heat exchanger (not shown) configured to use the waste heatfrom the engine's 602 water jacket may be used to, for example, preheatthe worked fluid 622, or heat the working fluid. It will be appreciatedthat a water jacket heat exchanger may be in addition to or in lieu ofthe engine's conventional air-to-fluid radiator heat exchanger. It ispreferred a temperature controlled valve (not shown) be used to controlthe volume or flow rate of engine coolant delivered to the water jacketheat exchanger so that the engine 602 is not overcooled. Also, as istaught herein with respect to other embodiments of my inventions, wasteheat from the engine's 602 mechanical or gas supercharger, if any, maybe captured.

It will now be appreciated that FIGS. 1-6B illustrate merely several ofmany possible embodiments of fluid heating systems (or subsystems) usingrotary heating devices, direct-fired heating devices, or electricheating devices. Those of skill in the art will be able to designclosed- or opened-loop fluid heating systems according to thisdisclosure for a wide variety of fluids and for a wide variety ofpurposes, as contemplated by this disclosure. For example, heating ofcorrosive or abrasive fluids may benefit from the closed-loop design ofFIGS. 2-6B, although the rotary heater, direct-fired heater or electricheater may be fabricated from corrosion and/or abrasion resistantmaterials, if desired, for opened-loop systems. In addition, thetemperature(s) to which the fluid is heated may determine whether aclosed- or open-loop system is desired. For example, the potential forand effects of scaling in the heat exchangers and/or heating devicesshould be considered in any design incorporating the present inventions.

A fluid heating system, such as those described above, may form asubsystem of a larger system, such as a fluid concentrating system, afluid evaporating system, a fluid separating system, and/or a fluidpasteurizing system, as discussed below. Any person of skill havingbenefit of this disclosure will know how to interchange the varioussubsystems disclosed herein to achieve a desired design goal. Inaddition, the fluid heating systems described herein may be also usedsimply to heat fluids, such as, without limitation, for paraffinflushing or for an oil well “kill” truck.

Turning now to fluid evaporation systems and methods, such systems maycomprise a flash tank in which the heated worked fluid is separated intovapor (e.g., steam) and liquid portions. The steam portion may be passedthrough an air-to-fluid heat exchanger to transfer heat from the steamto the air. The heated air may then be used to evaporate some or theentire liquid portion of the worked fluid.

FIG. 7 depicts one of many possible embodiments of a fluid evaporatingsystem 700. The system 700 may be characterized as comprising a heatingsection 702 and an evaporating section 704. In this embodiment, theheating section 704 comprises a rotary heating device 710, preferably acavitation-based rotary heater, such as described previously, coupled toan output of a prime mover 712, such as a diesel or most preferably anatural gas engine. Flex joints or other coupling mechanisms (not shown)may be used as needed to couple the engine 712 to the rotary heatingdevice 710. As will be described in more detail below, it is preferredthat the engine 712 cooling system, such as closed loop water jacket andradiator 714, be a component of the heating section 702.

The fluid to be evaporated 716 (i.e., the worked fluid), such asproduced water, is introduced to a tank 718 by any convenient means. Itis preferred that the tank 718 have a level control device 717 tocontrol the amount of fluid 716 supplied to the tank 718. The liquidphase of the fluid 716 is pumped by a circulation pump 720 to the rotaryheating device 710. It will be appreciated that the pump system 120 mayinclude one or more filters, filtration system or other discriminationdevices adapted to remove particulate matter from the fluid 716. Thetype and efficiency of the filtration system may be selected based onthe operational requirements of the rotary heating device 710 or otherheating system 702 component. In other words, particulate matter may beremoved as required to prevent damage to heating system 702 components.As the fluid 716 is pumped through the rotary heating device 710, thedevice 710 heats the fluid 716, such through as cavitation. Heated fluid722 is returned to the tank 718 The return conduit preferable includes avalve, orifice plate or other type of restriction device 724 to createsufficient backpressure in the heating section 702 to maintain sensibleheat in the fluid 722.

As heated fluid 722 enters the tank 718 it may flash, with a portion ofthe fluid 722 becoming steam and with the remainder being liquid. Thesteam portion 726 of the fluid 722 is communicated to a heat exchanger728, which is preferably a finned tube air-to-fluid condenser adapted toremove heat from the fluid 726. It is preferred that a demister 727 beused to ensure that the fluid 726 is clean vapor. As the fluid 726condenses, it collects and can be extracted from the heat exchanger 728by known means as condensate 730.

As shown in FIG. 7, ambient air 732 is forced through engine heatexchanger or radiator 714 to maintain the engine 712 at operatingtemperature. Heated air 734 may be passed through the condenser 728 tofurther heat the air by transferring heat from the fluid 726 asdescribed previously. The primary end product of heating system 702 isheated air 736.

Evaporation section 704 may comprise one or more evaporation chambers750. As illustrated in FIG. 7, evaporation section 704 comprises a firstevaporation chamber 752. In this chamber, a selected portion of theliquid phase 754 of fluid 722 is injected, such as by spraying, into thechamber 752. It is preferred that the chamber 750 be oriented such thatfluid 754 is sprayed or injected adjacent the top of the chamber 750 sothat the fluid falls through the heated air 736. A restriction device755, such as a valve and/or orifice plate, may be used to control thevolume of liquid fluid 754 introduced into the chamber 750. It ispreferred that the restriction device 755 be a variable flow ratecontrol valve adapted to receive control information form a liquid levelindicator in the chamber 750, as discussed below. A fluid 716 preheater(not shown), such as a fluid-to-fluid heat exchanger, may be used topreheat the fluid 716 with fluid heater fluid 754.

Heated air 736 is forced into and through the chamber to contact theliquid fluid 754. The heated air 736 causes a portion of the liquid 754to evaporate and exit the chamber 752 as heated moist air 756. Thatportion of the fluid 154 that does not evaporate collects in the bottomof the chamber 752. Because this collected fluid likely has some degreeof particulate contamination, it is desirable to agitate or stir thefluid, such as by fluid circulation. In a preferred embodiment, acirculation pump and filter system 758 is used to both agitate the fluidthat collects in chamber 752 and to filter out the particulatecontaminate 760, which can be disposed of as required and allowed.

Also shown in FIG. 7 is a second evaporation chamber 762. Chamber 762may use fluid collected in chamber 752 as shown by transfer conduit 764.Additional evaporative heat may be supplied to chamber 762 by exhaust766 from engine 712. Thus, chamber 762 uses moist heated air 756 andexhaust gases 766 to evaporate another portion of fluid 754. Theevaporated fluid is released from the chamber 762 as heated, moist air770. Chamber 762 may also include a circulation pump and filter system772 to both agitate the fluid that collects in chamber 762 and to filterout the particulate contaminate 774, which can be disposed of asrequired and allowed. The pump system 772 may also be used to re-inject(or re-spray) the fluid 754 in subsequent chambers.

As discussed above, evaporation section 704 comprises a fluid levelcontrol, preferably associated with chamber 762, so that the system 700is controlled to allow most of the fluid 754 entering evaporationsection 704 to be evaporated. Chamber 762 also includes a reduced waterblow down valve 776 that allows extraction and disposal of concentratedor reduced water, such as that portion of fluid 754 this is notevaporated.

Having now described an embodiment of a fluid evaporation system 700, itwill be apparent that the invention has multiple synergistic attributesand functionalities. For example, using the engine 712 exhaust gases 766to evaporate a portion of the fluid 722 also cleanses to a certaindegree the exhaust gases that are returned to the environment. Inaddition, it should be noted that the fluid 754 to be evaporated is theworking fluid as well.

A specific construction of the produced water evaporator systemdescribed above was designed to use a 36-inch diameter Shock Waver PowerReactor fabricated under license from Hydro Dynamics, Inc. The SPR wascoupled to a 600 horsepower natural gas engine having a fuel consumptionof 4,300 cubic feet per hour. The system was designed to accept up to7,250 pounds of produced water per hour (approximately 14.5 gallons perminute). The system 100 was designed to evaporate approximately 80% ofthe produced water input or 5,800 pounds/hour, and to createapproximately 1,450 pounds/hour of reduced (unevaporated) water fordisposal. The system 100 was also calculated to produce about 1,500pounds/hour (approximately 3.0 gallons per minute) of condensate ordistilled water. The finned tube condenser was designed to have aluminumfins on carbon steel tubes having about 6,800 square feet of surfacearea and adapted to exchange about 3,337,565 BTU/hour. The heatingsection was designed to operate at about 250° F. at about 35 psig. Anorifice or other restriction, such as valve 724, adjacent the flash tankis useful to maintain these operating conditions. The flash tank wasdesigned to operate at about 220° F. at about 10 psig. The condenser wasdesigned to output air heated to about 200° F. at a velocity of about 10feet per second.

The evaporator chambers were designed as a fiberglass tank having foursuccessive sections. In the first evaporative section, it wascontemplated that liquid from the flash tank would be sprayed into thechamber at about 150° F. TO 220° F. (depending, for example, on whethera fluid 716 preheater is used) in the presence of about 200° F. air. Twosuccessive chambers were designed to spray unevaporated liquid from theprior sections across the heated air flowing through the chambers. Thethird section was similarly designed. The last section utilized the heatenergy from the engine exhaust gases to aid further evaporation of thefluid. After passing through the four chambers, the heated air, ladenwith moisture from the fluid, was expelled from the system. As describedabove, reduced, unevaporated water, which is likely laden withparticulates, such as salts of sodium, magnesium and/or calcium,chlorides, sulfates and/or carbonates, may be expelled from theevaporation chamber 750.

It will be appreciated that whether to use the heat energy from theengine exhaust and whether to use one or multiple evaporation chambersor process sections is a matter of design choice based upon numerousdesign criteria well within the capabilities of those of skill in thisart having benefit of this disclosure.

FIG. 8 illustrates an embodiment of a fluid evaporating subsystem 804.It will be appreciated that FIG. 8 is based on the embodiment shown inFIG. 7. In fact, the reference numbers used in FIG. 7 directly translateto those used in FIG. 8. For example, reference number 814 identifiesstructure similar to that shown as 714 in FIG. 7.

The modifications disclosed in FIG. 8 involve using two separateevaporation chambers 852, 862. Chamber 852 is a “clean” evaporationchamber in that the evaporating air 836 is air heated by the condenser828. Rather than the optional filtration system 758 described in FIG. 7,FIG. 8 makes use of particle separating system 859, which may comprise aparticulate separator, such as a hydrocyclone separator, and a settlingbin. The particulate matter 860 that is recovered from system 859 is“clean” in that it will have little to no atmospheric contamination and,to the extend a market exists, the particulates recovered may be reusedor sold.

The second evaporation chamber 862 is a “dirty” chamber in that engineexhaust gases 866 are used in conjunction with air 834 heated by engineradiator 814 to evaporate fluid 864. It is believed that themodifications disclosed in FIG. 8 results in a better heat balance thanthe embodiment disclosed in FIG. 7. Also shown in FIG. 8, the “dirty”chamber 862 may use a particle separating system 873 as described above.

Illustrated in FIG. 9 is an embodiment of an evaporation system 900particularly suited for evaporating water produced from subterraneanwells or mines. Shown generally by dashed line is a heating subsystem902 (as described below, flash tank 904 is rightly considered a part ofthe evaporation subsystem 906 and not the heating subsystem 902, andengine jacket heat exchanger 907 is rightly a part of the heatingsubsystem 902).

Closed-loop heating subsystem 902 comprises a rotary generator 908,preferably a natural gas or diesel engine, coupled to a rotary heatingdevice 910, preferably a water brake dynamometer. The rotary heater 910is plumbed in closed-loop fashion to a tank 912 that is vented to theatmosphere, a circulation pump 914, such as a centrifugal pump, anengine exhaust gas 960 heat exchanger 916, engine jacket heat exchanger907 and a primary heat exchanger 918. It will be appreciated that theheating subsystem 902 may comprise any of the heating subsystemsdescribed with reference to FIGS. 1-8.

Also shown in FIG. 9 is rotary heater bypass 920 and bypass valve 921.In a preferred embodiment, the temperature T3 of the working fluid as itenters the primary heat exchanger 918 is used to control the position ofthe bypass valve 921 to maintain the temperature of the working fluid ata desired point, such as at a temperature below its atmospheric boilingpoint.

Also illustrated in FIG. 9 is an evaporating section 906 comprising ainlet 930 for the worked fluid (i.e., the fluid that is subject toevaporation), a positive displacement feed pump 932, preferably a Moynometering pump, and a fluid-to-fluid heat exchanger 934 adapted topreheat the worked fluid with heat from the engine jacket coolant.Preheated worked fluid is pumped 935 to the primary heat exchanger 918where it picks up additional energy from the heating subsystem 902. Theheated worked fluid is pumped to the flash tank 904 through orifice orvalve 936, which is selected to maintain sufficient pressure in thesystem to prevent the fluid from flashing (i.e., vaporizing) until itenters the flash tank 904. It is preferred that the flash tank operateat negative atmospheric pressure, typically around about 0.9 to 2.5 psia(i.e., a vacuum of about 25 to 28inches of mercury). A vacuum system938, such as a liquid ring pump, may be used to maintain the vacuum inthe flash tank. It will be appreciated that as heated fluid enters theflash tank 904 a portion flashes off into steam (or vapor), which isdrawn by vacuum system 938 to an air-to-fluid heat exchanger 940,preferably a finned tube heat exchanger. Ambient air 942 a is forcedthrough heat exchanger 940 to transfer heat from the fluid vapor to theair 942 a. As will be described below, the heated air 942 b will be usedto evaporate fluid that collects in the flash tank 904.

The transfer of heat in heat exchanger 940 causes the fluid vapor tocondense to liquid, which is collected in a condensate receiver 944. Itis preferred that the condensate receiver 944 be equipped with a fluidlevel control adapted to control a condensate pump 946. The levelcontrol and pump 946 may be configured to maintain a relatively fixedfluid level in condensate receiver 944. It will be appreciated thatcondensed fluid 948, for example water, may be used for various purposesas needed (e.g., for desuperheating purposes) or disposed of as allowed.

Returning to the heat exchanger 940, heated air 942 b exits the heatexchanger 940 and a portion is forced through the engine jacket heatexchanger or radiator 907, where the air 942 b picks up additional heat.This heated air 942 c along with the remainder of the air 942 b isforced through one or more evaporation chambers 950. Evaporation chamber950 may be considered a “clean” chamber insofar as the heated air 942 cis relatively clean, typically having only natural contaminants, such asdust, pollen and the like.

A fluid pump 952, such as a variable positive displacement pump, iscoupled to the flash tank 904 so that collected fluid, i.e. liquid, ispumped to evaporation chamber 950. It is preferred that spray nozzles orother types of misting or spraying devices be used to spray or mistflash tank 904 fluid inside chamber 950. In a preferred embodiment, oneor more spray nozzles are located adjacent an upper surface of thechamber 950. Also in the preferred embodiment, heated air 942 c isforced to flow substantially normal or perpendicular to the sprayedfluid to thereby evaporate at least a portion of the liquid. It will beappreciated that suitable baffles or other contact surfaces can beinstalled in chamber 950 to minimize or eliminate condensed fluid fromexiting chamber 950 with heated moist air 942 d.

Unevaporated fluid collects in the chamber 950 and a circulation pump954 may be used to recirculate this fluid through the chamber foradditional evaporation. Additionally, if desired, the fluid can bepassed through a filtration or separation system 956 to removeparticulates 957 from the fluid. It is preferred that separation system956 comprises a hydrocyclone. Excess fluid from system 956 can bereturned to the chamber 950 for evaporation. Recovered particulates 957can be disposed of as allowed, or if a market exists for such recoveredparticulates, for example, for gypsum, sold.

If only one evaporation chamber 950 is utilized, it is preferred thatchamber 950 comprise a fluid level control device adapted to controlfluid pump 952, preferably a positive displacement pumps such as thoseoffered by Moyno, to maintain the fluid flow and evaporation throughchamber 950 at a desired level.

Optionally, an additional evaporation chamber 958 may be utilized asdesired. This evaporation chamber 958 may be described as a “dirty”chamber in that exhaust gasses from rotary generator 908 (e.g., naturalgas or diesel engine) may be used to further evaporate fluid.

Exhaust gasses 960 from the heat exchanger 916 are introduced, alongwith warm, moist air 942 d, if desired, into chamber 958. Chamber 958may be designed similarly to chamber or chamber 950. Fluid to beevaporated may be drawn from chamber 950 and sprayed or otherwisecontacted with air 942 d and gasses 960 to evaporate at least a portionof the fluid. Chamber 958 may likewise comprise a circulation pump 962and filter/separation system 964, as desired. It will be appreciatedthat an additional benefit of “dirty” chamber 958 is that it can be usedto scrub or clean the exhaust gasses 960 prior to discharge into theenvironment.

It will be appreciated that system 900 can be designed and operated toevaporate all of the fluid input into the system or only a portion ofthe fluid inputted. For those systems where less than completeevaporation is desired or required, evaporation chamber blowdown may beextracted and disposed of as allowed and required. For systems utilizingscrubbing of the exhaust gasses, disposal of at least a portion of theblowdown will likely be required.

FIGS. 10 and 11 illustrate alternate embodiments of fluid evaporatingsystems and methods. The detailed description set forth above withrespect to FIG. 9 substantially applies to FIGS. 10 and 11 with commonstructures having similar reference numbers. For example, in all ofFIGS. 9, 10 and 11, the flash tank is identified by reference number904, 1004 and 1104, respectively.

Concerning FIG. 10, incoming fluid 1030 is mixed with fluid from theflash tank 1004 and then split with a portion flowing directly toprimary heat exchanger 1018 and back to the flash tank 1004, and theother portion diverted to the evaporation chamber 1050 for evaporation.In one embodiment, as the amount of total dissolved solids, TDS, in theflash tank increases, more fluid is diverted to the evaporation chamber1050, which allows more new fluid 1030 to enter the system. For example,a TDS instrument 1033 may be used to control flow device 1037 based onthe TDS value determined.

Additionally, FIG. 11 discloses the flash tank having a demister hood1139 to ensure that the vapor conducted to the heat exchanger 1140 isrelatively dry. In addition, chamber 1150 is disclosed as having anagitator system 1151 to keep any particulate matter suspended in theliquid fluid for removal by systems 1156 and 1157. FIG. 11 also shows adesuperheating inlet 1141 allowing the introduction of fluid, if needed,such as condensate, to desuperheat the steam entering the condenser1140.

In the embodiment shown in FIG. 11, inlet pump 1132 may be controlled bya fluid level control associated with flash tank 1104, and evaporatorpump 1152 may be controlled by the TDS of the fluid in the flash tank104 and/or a fluid level control in the evaporator reservoir 1150. Theembodiment shown in FIG. 11 may be operated to achieve substantiallycomplete evaporation of the inputted fluid.

An embodiment of an evaporator system utilizing aspects of the presentinventions was designed for produced water having total dissolved solidsof about 9,000 parts per million. A 600 horsepower natural gas enginewith a fuel consumption of 4,300 cubic feet per hour was selected as theprime mover. The system was designed to accept up to 7,135 pounds ofproduced water per hour (approximately 14.3 gallons per minute). Thesystem was designed to evaporate approximately 100% of the producedwater input or 7,135 pounds/hour, and to create approximately 2,651pounds/hour condensate for use or disposal. The system was calculated toproduce about 1,500 pounds/day of solids for disposal. The finned tubecondenser was designed to have aluminum fins on carbon steel tubeshaving about 6,800 square feet of surface area and adapted to exchangeabout 3,337,565 BTU/hour. The heating section was designed to operate atbetween about 150 and 180° F. at about atmospheric pressure. The flashtank was designed to operate at about 130 to 170° F. at about 25 inchesof mercury (vacuum). The condenser was designed to output air heated toabout 130° F. at a velocity of about 60,000 cfm.

As will now be appreciated, FIGS. 9, 10 and 11 illustrate merely threeof many embodiments of a fluid evaporator comprised of a flamelessheating subsystem and an evaporation subsystem. Depending upon thecharacteristics of the fluid to be evaporated (the worked fluid), theenvironment in which the system will be used and economicconsiderations, the evaporation system may be designed and operated toevaporate substantially all of the worked (e.g., produced water) or onlya portion of the worked fluid, with the remainder being disposed of, ifnecessary, by allowable and economic means.

It will also be appreciated that any of the embodiments illustrated anddescribed in FIGS. 7-11 may be implemented with any of the variousheating subsystems described herein, including, but not limited to, arotary heating subsystem, a direct fired or open flame heating system oran genset/electric boiler subsystem.

FIG. 12A illustrates a fluid evaporating system and method comprising adirect-fired heating subsystem coupled to a single chamber evaporationsubsystem. For all intents and purposes, the systems illustrated inFIGS. 11 and 12A are the same except that the fluid heating subsection1202 in FIG. 12A is direct fired. Thus, the description and operation ofthe fluid evaporating subsystem in FIG. 11 applies to the fluidevaporating subsystem of FIG. 12, where like structures have likenumbers. For example, flash tank is 1104 in FIGS. 11 and 1204 in FIG.12A.

Concerning the fluid heating system 1202, this subsystem is similar tothe fluid heating system illustrated and described in FIG. 6. Theheating system 1200 comprises a direct-fired fluid heater 1204, which ispreferably a 5,000,000 BTU/hr natural gas water heater, such as a ParkerBoiler Model 6200. It is contemplated that the heater 1204 would befired with waste gas from the field metered into the heater 1204 throughpressure control valve 1206. Therefore, it is desirable that the heater1204 burner controls (not shown) allow for substantially real-timegas-to-air adjustments to account for changing gas quality. The workingfluid in the closed-loop heating circuit is preferably a 50/50 mixtureof water and glycol. The heater 1204 heats the working fluid totemperature T1, which may be, for example, 210° F. The heated workingfluid is pumped 1208 through a fluid-to-fluid heat exchanger 1210 totransfer heat from the working fluid to the worked fluid. Working fluidexits the heat exchanger 1210 and enters an atmospheric reservoir oraccumulator 1214. Pump 1208 draws working fluid out of the reservoir1214 and feeds it back to heater 1204. A temperature transducer T1cooperates with controllable valve 1206 to control the temperature ofthe working fluid. In the system illustrated in FIG. 12A, the workedfluid may be heated to about 170° F.

FIGS. 12B and 12C illustrate other fluid concentrating systems 1200 inaccordance with aspects of the present inventions using multiple-effectevaporation. As is known, multiple-effect evaporation is an evaporationprocess for efficiently using the heat from steam to evaporate water. Ina multiple-effect evaporator, water is boiled in a sequence of vessels,each operated at a successively lower pressure. Because the boilingtemperature of water decreases as pressure decreases, the vapor (i.e.,steam) boiled off in one vessel can be used to heat the next, and onlythe first vessel, which operates at the highest pressure requires anexternal source of heat. Evaporation systems with more than four stagesare rarely practical, although some multiple-effect systems have up toseven stages.

As illustrated, the fluid evaporating system 1200 of FIG. 12B comprisesa heating subsystem 1202, such as any of those described above withrespect to FIGS. 1-6. The particular fluid heating subsystem 1202illustrated in FIG. 12B is a closed-loop subsystem similar to thatillustrated in and described by FIGS. 6 and 12A. The reference numbersand descriptions used for FIG. 12A are applicable to FIG. 12B as well.For example, direct-fired heater 1204 in FIG. 12A is direct fired heater1204 in FIG. 12B. The heating subsystem show in FIG. 12B is preferablyconfigured to achieve a 750 gallon/minute flow rate.

The fluid evaporating system 1200 also comprises an evaporatingsubsystem 1203. In subsystem 1203, pressurized and metered fluid 1220 iscirculated to primary heat exchanger 1210 where the fluid 1220 is heatedby the working fluid from heating subsystem 1202. Heated fluid 1220 ispassed through an orifice or valve 1226 adapted to create a pressuredifferential across the device 1226. The fluid 1220 is flashed into tank1228 where it is separated into its vapor and liquid phases. The flashtank 128 is preferably operated under negative atmospheric pressure ofabout 6.4 psia (i.e., a vacuum of about 17 inches of mercury). A vacuumsystem 1230, such as a liquid ring pump, may be used to maintain thesystem vacuum.

The vapor phase of fluid 1220, such as steam at about 172° F., is passedthrough a heat exchanger 1270, which may be a fluid-to-fluid heatexchanger. Heat exchanger 1270 functions to transfer heat from the firstevaporation stage to the second evaporation stage. In the second stage,pressurized and metered fluid 1220 is circulated to heat exchanger 1270where the fluid 1220 is heated by the steam from the first evaporationstage. Heated fluid 1220 is passed through an orifice or valve 1272adapted to create a pressure differential across the device 1272. Thefluid 1220 is flashed into tank 1274 where it is separated into itsvapor and liquid phases. The flash tank 1274 is operated underatmospheric pressure less than the operating pressure of tank 1228(first stage tank), e.g., at about 3.2 psia (i.e., a vacuum of about23.5 inches of mercury). A vacuum system 1276, such as a liquid ringpump, may be used to maintain the system vacuum.

The vapor phase of fluid 1220, such as steam at about 135° F., may bepassed through a heat exchanger 1278, which may be an air-to-fluid heatexchanger. The steam, or a portion thereof, is condensed by heatexchanger 1278 and passed to a condensate receiver 1234, which,preferably is operated under vacuum to remove any volatile components.Any such volatiles may be feed as fuel to the heating subsystem 1202. Acondensate pump may be used to remove the condensate, e.g., distilledwater, from the condensate receiver.

Similarly, the steam entering heat exchanger 1270 is condensed and maybe collected in receiver 1234.

Referring back to flash tanks 1228 and 1274, concentrated liquidaccumulates in each tank and may be circulated by pumps 1224. A meteringand detecting system may be used to assess, determine or calculate oneor more properties of the concentrated fluid. For example, a system canbe implemented to determine the temperature, density, specific gravity,conductivity, flow rate or other property or characteristic of theconcentrated fluid. An extraction system 1241, such as a variable speedpump may be adapted to extract the desired concentrated fluid from thesystem 1200 when it has the desired properties. A metering device may beused to determine the amount of concentrated fluid removed from thesystem.

Also, as illustrated in FIG. 12B, concentrated fluid from tank 1228, atabout 172° F. is mixed with incoming fluid 1220 to raise the fluidtemperature before it enters primary heat exchanger 1218. Similarly,concentrated fluid from tank 1274, at about 144° F. is mixed withincoming fluid 1220 to raise the fluid temperature before it enters heatexchanger 1270.

It will now be appreciated that the system illustrated in FIG. 12B canbe used to evaporate fluids, such as produced water or flowback. Forexample, it is is postulated that the system illustrate in FIG. 12B canprocess about 875 barrels of produced water having a total dissolvedsolids of 60,000 ppm into about 688 barrels of distilled water and 210barrels of 10 lb_(f) Brine solution every 24 hours. The optional spraychamber 1290 illustrated in FIG. 12B will dispose of another 250 barrelsof produced water in a 24 hour period.

Oftentimes, an amount of fluid to be evaporated or processed will bestored in large volumes in an open pit, storage device, tank, or otherretention area. Usually such storage device will be open to atmosphere,such that the fluid will exist at ambient temperature and ambientpressure. It is preferred, but not necessary, that solids be allowed tosettle out and lighter components, such as oil or other hydrocarbons, tobe skimmed off for use or sale. The fluid of interest can then besuctioned out of the tank.

An additional stage of evaporation may be achieved by replacing theair-to-fluid condensing heat exchanger, such as, but not limited to,condenser 1278 in FIG. 12B, with a fluid-to-fluid heat exchanger, suchas, but not limited to, a plate and frame heat exchanger and using theuntreated fluid in the storage device for cooling. FIG. 12C, for whichreference to the description of FIG. 12B should be made, illustrates asystem 1203 with a fluid-to-fluid condensing heat exchanger 1279. Afterpassing through the fluid-to-fluid heat exchanger 1210, the heateduntreated fluid may be sprayed or passed over an inclined plate on itsreturn to the retention area. This addition would utilize the absorbedheat to evaporate an additional portion of the fluid. Heat not removedby the latent heat of evaporation would be recovered as preheatedincoming fluid to the evaporation or other fluid manipulating system.Those of skill will appreciate that the cost of an air-to-fluid heatexchanger typically will be higher than a fluid-to-fluid heat exchangerfor the modification discussed here.

It will also be appreciated that the evaporator systems can be used toremove (by evaporation) fluid from the worked fluid to effectivelyconcentrate the worked fluid. The concentrated fluid can be extractedfrom one or more of the evaporation spray chambers. It will also beappreciated that it may not be desirable to concentrate certain workedfluids (e.g., a diluted well completion fluid) by forcing heated ambientair through the fluid. Particles entrained in the air, such as dirt,dust, pollen, or exhaust gasses may contaminate the worked fluid.

It will be appreciated that the evaporator systems described herein alsoproduce a “blowdown” fluid, such as the liquid in the flashtank(s).Depending on the raw fluid from which water is evaporated, the blowdownmay be a desirable product. For example, when evaporating producedwater, the blow down likely will be a concentrated brine solution, whichhave many oil field uses. As shown in the various Figures provided withthis disclosure and as discussed herein, a measurement device or metermay be used to determine one or more properties of the flash tank liquidphase, so that the liquid phase, or a portion of the liquid phase, maybe withdrawn when the desired fluid properties are reached. For example,meter 1280 is illustrated in FIGS. 12A, 12B and 12C. A measurementdevice that is presently preferred for all my inventions disclosedherein is the ProMass line of flow meters offered by Endres+Hauser.

Thus, my inventions can be adapted to create a fluid concentratorsubsystem comprising a flash tank in which the heated worked fluid isseparated into vapor (e.g., steam) and liquid portions. The steamportion may be passed through an air-to-fluid heat exchanger to condensethe steam back to liquid. The condensed liquid may be removed from theworked fluid thereby concentrating the worked fluid.

Turning now to FIGS. 13A and 13B, embodiments of a fluid concentratingsubsystem 1300 are presented. These two embodiments utilize primary heatexchangers 1304 that separate the working fluid 1302 heating subsystem1303 from the concentrating subsystem 1301. It will be appreciated thatany of the foregoing heating subsystems described with respect to FIGS.1-12C may be used with the fluid concentrating subsystems illustrated inFIGS. 13A and 13B. FIG. 13B illustrates a direct-fired heating subsystem1303.

It also will be appreciated from this disclosure that an opened-loopfluid concentrating system may be designed by, among other things,eliminating the primary heat exchanger 1304. For example, theopened-loop fluid evaporating system of FIG. 7 can be modified accordingto the teaching of this disclosure to produce an opened-loop fluidconcentrating system.

Returning to FIGS. 13A and 13B, diluted fluid (aka the “worked” fluid),such as a completion fluid recovered from a well, 1305 is introducedinto the system 1300. A metering system 1306 may be used to determinethe amount of diluted fluid introduced. A circulation pump 1308 is usedto circulate the diluted fluid through the primary heat exchanger 1304to pick up heat from the heating subsystem 1303. The heated, dilutefluid 1305 flows through a valve or other flow restriction device 1310configured to create a pressure differential across the device 1310 ofabout 30 psid. The fluid 1305 is flashed into tank 1312 where the fluidis separated into its vapor and liquid phases.

The flash tank 1312 is preferably operated under negative atmosphericpressure of about 0.9 to 2.5 psia (i.e., a vacuum of about 25 to 28inches of mercury). A vacuum system 1314, such as a liquid ring pump,may be used to maintain the system vacuum. The vapor phase of fluid1305, such as steam, is passed through a heat exchanger 1316, which maybe a fluid-to-fluid or air-to-fluid heat exchanger. Heat exchanger 1316functions as a condenser to condense the fluid vapor to its liquidphase, e.g., water. The condensed fluid 1317 is collected in a reservoir1318. Alternately, the condensate can be used to preheat the incomingfluid 1305. It is preferred that reservoir 1318 be equipped with a levelcontrol system that controls a condensate pump 1320. It will beappreciated that the condensate that is produced by system 1300 isrelatively clean and may be used for a variety of purposes or discardedas allowed.

Referring back to flash tank 1312, concentrated liquid fluid 1342accumulates in the tank and may be withdrawn by a fluid extraction andmetering system 1322, such as described below with respect to FIGS. 15and 16.

In addition to being coupled to opened-loop or closed loop heatingsubsystems, such as those described above with reference to FIGS. 1-6,the fluid concentrating subsystem embodiments described in FIGS. 13A and13B are particularly suited for use on offshore drilling or productionplatforms. FIG. 14 illustrates a fluid concentrating system adapted foran offshore rig, in which the heating subsystem 1402 (not shown)comprises the stationary engines of the rig. The description withrespect to FIGS. 13A and 13B apply to like structures in FIG. 14. Insuch application, an existing thermal energy source from the rig orplatform may be utilized. For example, and preferably, the primaryworking fluid 1302, 1402 is preferably a fluid heated by conventionalrig equipment, such as one or more internal combustion engines. Forexample, the working fluid may comprise the liquid coolant from dieselengines (e.g., water jacket coolant).

FIGS. 15 and 16 illustrate fluid concentrating systems 1500 and 1600 inaccordance with aspects of the present inventions. For purpose of thisdescription, like elements have like reference numerals. Thus, forexample, the condensate reservoir is referenced as structures 1534 and1634 in FIGS. 15 and 16, respectively. While only reference numbersfound in FIG. 15 may be described, this description will be understoodto apply equally to similarly referenced elements in FIG. 16.

The fluid concentrating system 1500, 1600 comprises a flameless heatersubsystem 1501, 1601, such as those described above with respect toFIGS. 1-6. The particular fluid heating subsystem illustrated in FIGS.15 and 16 is a closed-loop subsystem similar to that illustrated in anddescribed by FIG. 2. The reference numbers and descriptions used forFIG. 2 are applicable to FIGS. 15 and 16 as well. For example, rotaryheating device 204 in FIG. 2 is rotary heating device 1504 in FIGS. 15and 1604 in FIG. 16.

The fluid concentrating system 1500, 1600 also comprises a concentratingsubsystem 1503, 1603. In subsystem 1503 and 1603, fluid to beconcentrated 1520 (aka, the “worked” fluid) is preheated in heatexchanger 1522, which is adapted to transfer heat from the condensedfluid, as will be described below, or from the engine 1502 water jacketas described previously. Pressurized and metered fluid 1520 iscirculated to primary heat exchanger 1518 where the fluid 1520 is heatedby the working fluid from heating subsystem 1501. Heated fluid 1520 ispassed through an orifice or valve 1526 adapted to create a pressuredifferential across the device 1526 of about 30 psid. The fluid 1520 isflashed into tank 1528 where it is separated into its vapor and liquidphases. The flash tank 1528 is preferably operated under negativeatmospheric pressure of about 0.9 to 2.5 psia (i.e., a vacuum of about25 to 28 inches of mercury). A vacuum system 1530, such as a liquid ringpump, may be used to maintain the system vacuum.

The vapor phase of fluid 1520, such as steam, is passed through a heatexchanger 1532, which may be a fluid-to-fluid or air-to-fluid heatexchanger. Heat exchanger 1532 functions as a condenser to condense theworked fluid vapor to its liquid phase. The condensed worked fluid iscollected in a reservoir 1534 and, as mentioned above, may be passedthrough preheater 1522 to preheat the fluid 1520 (and to cool thecondensate). As shown in FIGS. 15 and 16A, the preheater 1522, 1622utilizes water jacket coolant from engine 1502, 1602. It is preferredthat reservoir 1534 be equipped with a level control system thatcontrols a condensate pump 1536. It will be appreciated that thecondensate that is produced by system 1500 is relatively clean and mayused for a variety of purposes or discarded as allowed.

Referring back to flash tank 1528, concentrated liquid fluid accumulatesin the tank 1528 and may be circulated by pump 1524. A metering anddetecting system 1540 may be used to assess, determine or calculate oneor more properties of the concentrated fluid. As previously mentioned,the Promass line of flow meters offered by Endres+Hauser are suitablefor this implementain. For example, system 1540 can be adapted todetermine the temperature, density, specific gravity, conductivity, flowrate or other property or characteristic of the concentrated fluid. Anextraction system 1541, such as a variable speed pump controlled bysystem 1540 may be adapted to extract the desired concentrated fluidfrom the system 1500. A metering device may be used to determine theamount of concentrated fluid removed from the system.

A valve or other flow-restricting device 1538 may control the amount ofincoming fluid 1520 allowed into the subsystem 1503, which valve may becontrolled by a fluid level device in flash tank 1528. In other words,additional fluid is allowed into subsystem 1503 to maintain a desiredlevel of fluid in flash tank 1528. As fluid is extracted from thesubsystem 1503 through valve 1542, the liquid level in tank 1528decreases thereby allowing more fluid 1520 into the system. To theextent it is desired to cool extracted concentrated fluid, such fluidmay be used, for example, to preheat incoming fluid 1520.

Also illustrated in FIGS. 15 and 16 is an optional desuperheat inletinto heat exchanger 1532, 1632. In the event the steam entering the heatexchanger is superheated, fluid, such as liquid water, can be introducedthrough valve 1550, 1650 to desuperheat the steam. Condensate removedfrom the system can be used for this purpose.

FIG. 17 illustrates a fluid separating system 1700 according to aspectsof the invention previously described, such as in FIGS. 1-16, and likestructures have similar reference numbers. For example, in FIG. 16 thefluid heat exchanger is reference number 1618 and in FIG. 17 it is 1718.System 1700 incorporates a fluid separation tower or fluid fractionatingtower 1775 to separate the heated fluid into some or all of its boilingpoint fractions. As is well known in the art, fractionating columnsseparate a fluid mixture by condensing vapor fluids in accordance withRaoult's law. Each condensation-vaporization cycle causes fluid vapor ofa particular boiling point to be separated out. Fluid exiting the top ofthe column 1775 is vapor and is passed to condenser 1732 to be condensedback to a liquid. The condensed liquid 1780 may be reinjected into thecolumn 1775 through reflux lines 1782. It will be appreciated thatconcentrated fluid 1784 exits system 1700 from the bottom of the columnor tower 1775.

FIG. 18 illustrates another fluid separating system 1800 in which theengine 1802 drives an electrical generator 1860, such as described withreference to FIG. 3, rather than rotary heater 1704. The energygenerated by generator 1860 is used, at least, to heat the working fluidin an electrical heater 1862. In all other material respects, theembodiments illustrated in FIGS. 17 and 18 are similar.

As with other systems described herein, it is preferred, but notrequired that the worked fluid be limited to temperatures below itsatmospheric boiling point. Thus, it is preferred that the systems beoperated under vacuum. However, this is not required and is left to thedesign considerations of the particular system being implemented.

FIGS. 19A and 19B illustrate yet other embodiments utilizing variousaspects of the inventions disclosed and taught herein. FIGS. 19A and 19Billustrate systems 1900 that may be used to “pasteurize” a fluid, suchas industrial or oil field fluids. “Pasteurize,” in the context of thisdisclosure, means to hold a fluid at a temperature, or above atemperature, for a period, or for at least a period, to destroyobjectionable organisms in the fluid, without causing major chemical orfunctional alteration of the fluid. As an example, but withoutlimitation or definition, a fluid may be “pasteurized” using system 1900by holding the fluid for at least 15 seconds at a temperature of atleast about 161° F.

In general, the system 1900 heats a fluid, such as, but not limited to,oil well fluids, to a temperature above 161° F. by passing the fluidthrough a fluid-to-fluid heat exchanger that is coupled to a heatingsubsystem. The heated fluid may then be flashed into its liquid andvapor forms through an orifice into a holding tank, where the liquid isheld for at least about 15 seconds and preferably longer. It ispreferred, but not required, that the tank be operated under negativepressure (i.e., a vacuum) to, among other things, remove oxygen andother gasses from the liquid. The vapor phase may pass through ademisting hood in which entrained liquid is separated and returned tothe tank. The vapor (e.g., steam) may be passed to a fluid-to-fluid heatexchanger that functions to transfer heat from the vapor to the incomingfluid stream. The condensed vapor may be captured in a condensatereceiver. After the degassed liquid portion has been held in the tankfor 15 seconds or more at 161° F. or higher, the liquid portion may beremoved and pumped through another fluid-to-fluid heat exchanger thatmay also function to transfer heat from the vapor to the incoming fluidstream and concomitantly cool the degassed, pasteurized fluid. Althoughthe vapor portion and the degassed liquid portion may be used to heat(or preheat) the incoming fluid, the majority of the heating may occurin the fluid-to-fluid heat exchanger that that is coupled to a heatingsubsystem, such as any of those previously described with reference toFIGS. 1-18.

In this fashion, system 1900 is able to concentrate, pasteurize, degasand/or de-oxygenate a fluid, to prevent or minimize growth ofobjectionable aerobic and anaerobic organisms in the fluid.

Without limitation, the specific embodiment shown in FIG. 19A utilizes adirect-fired, closed loop, heating cycle 1902. FIGS. 6 and 12 illustratepreferred embodiments of a direct-fired, closed loop heating subsystemsthat may be used with system 1900. It will be appreciated that otherheating subsystems, such as one or more of those disclosed herein, maybe used based on the performance objectives of system 1900 to beachieved. As shown in FIGS. 6 and 12, the closed-loop heating subsystemmay comprise a natural gas or other hydrocarbon-based boiler for heatinga working fluid. It is preferred that the direct-fired fluid heater 1904be a 5,000,000 BTU/hour natural gas water heater. It is contemplatedthat in certain applications the heater 1904 would be fired with wastegas from an oil field metered into the heater 1904 through a pressurecontrol valve 1906. Therefore, it is desirable that the heater1904-burner controls allow substantially real-time gas-to-airadjustments to account for changing gas quality.

The working fluid in the closed-loop heating subsystem 1902 ispreferably a 50/50 mixture of water and glycol. The heater 1904 may heatthe working fluid to temperature T1, which may be, for example, 210° F.The heated working fluid is pumped 1908 through a fluid-to-fluid heatexchanger 1910 to transfer heat from the working fluid to the workedfluid. Working fluid exits the heat exchanger 1910 and enters anatmospheric reservoir or accumulator 1914. Pump 1908 draws working fluidout of the reservoir 1914 and feeds it back to heater 1904. Atemperature transducer T1 cooperates with controllable valve 1906 tocontrol the temperature of the working fluid.

The fluid 1903 to be pasteurized (aka the “worked fluid”) enters system1900 at pump 1950, which may be, among other things, a conventionalcentrifugal pump. A controllable valve 1952, such as a globe valve, maybe positioned after the pump 1950 to control the temperature of theworked fluid exiting the heat exchanger 1910. As shown in FIG. 19, atemperature transducer T3 adjacent the exit of heat exchanger 1910 maybe used to control valve 1952 in known fashion.

Typically, the worked fluid 1903 will enter the system 1900 attemperature between about 40° F. and 80° F. It is preferred, but notrequired that the incoming worked fluid 1903 be pre-heated. One sourceof energy for a pre-heater is the pasteurized worked fluid. As shown inFIG. 19A, the liquid portion of worked fluid 1903 exits the flash tank1928 at between about 161° F. and 171° F., and preferably about 162° F.It is often desirable to cool this pasteurized fluid before it exitssystem 1900, and this fluid can be used to pre-heat the incoming fluid.A fluid-to-fluid heat exchanger 1954 can be used to transfer energy fromthe pasteurized fluid exiting the flash tank 1928 and to the incomingfluid. For example, and not for limitation, worked fluid entering thepre-heater 1954 at about 162° F. may be cooled to about 90° F. and theincoming fluid may be heated to about 130° F.-132° F.

Similarly, as will be discussed in more detail below, the vapor portionof the worked fluid from the flash tank 1928 can be used to preheat (orheat) further the incoming fluid by passing the vapor (e.g., steam)through a condensing heat exchanger 1932. For example, the vapor portionof the worked fluid may exit the flash tank at a temperature of about162° F. and transfer some of its thermal energy in heat exchanger 1932to the worked fluid, raising its temperature to about 142° F.

Regardless of the number of preheating stages used and regardless of thetemperature of the incoming fluid, the worked fluid is primarily heatedin fluid-to-fluid heat exchanger 1910 which thermally couples theincoming worked fluid 1903 to the heating subsystem 1902. Thetemperature of the worked fluid exiting the primary heat exchanger 1910may be controlled by inlet valve 1952, which may be controlled based onthe temperature of the exiting worked fluid. As discussed above, it ispreferred that the temperature of the worked fluid exiting the primaryheat exchanger 1910 is above 161° F. and preferably is about 172° F. Ithas been found that at temperatures above about 175° F., scaling of theinternal surfaces of the heat exchangers and flash tank may occur. Oncethe worked fluid is at temperature, it is flashed into its vapor andliquid portions through orifice 1956 and into flash tank 1928. A baffle1958 may be located in flash tank 1928. The liquid portion of the workedfluid 1903 settles in the bottom of the flash tank 1928 as shown in FIG.19. A liquid level transducer 1960, such as a guided wave transducer maybe used to sense the liquid level in the tank.1928. Once the liquidlevel in the flash tank reaches a certain height, such as, for example,halfway, pump 1962 and controllable valve 1964 are energized and openedto extract pasteurized liquid from the flash tank 1928, which fluid maybe passed through pre-heater 1954, as previously described, to bothpreheat the incoming fluid and cool the exiting worked fluid.

It will be appreciated that holding the worked fluid in flash tank 1928at a temperature of about 172° F. for a period greater than 15 secondswill effectively pasteurize the worked fluid and kill all orsubstantially all of the aerobic and anaerobic objectionable organismsthat may exist in the fluid.

In addition, it is preferred that the flash tank 1928 be operated at asub-atmospheric pressure, such as, but not limited to 18 inches ofvacuum. By operating the flash tank under a vacuum, oxygen and othergasses will be removed from the liquid portion of the worked fluid,along with the vapor portion of the worked fluid. It will be appreciatedthat by depleting or decreasing the amount of oxygen in the workedfluid, objectionable organisms may be destroyed and/or the ability ofobjectionable organisms to grow in the worked fluid will be minimized.The liquid may be agitated in known manner, as necessary, to achievemaximum de-oxygenation of the fluid.

As previously discussed, the vapor phase of the worked fluid and anygasses removed from the liquid portion of the worked fluid will passthrough demister hood 1966 in which any entrained liquid will beseparated from the vapor and returned to the flash tank. Thereafter, thevapor (e.g., steam) may be passed through a condensing heat exchanger tocondense the vapor to its liquid form (e.g., distilled water) andconcomitantly transfer heat to the incoming fluid. The exit of thecondenser 1932 may be coupled to a condensate receiver and vacuum pump1968. Any non-condensable gasses, such as oxygen, nitrogen (air) andlight hydrocarbons may be passed to, for example, the direct firedboiler for incineration or combustion.

Having now described the basic layout of the embodiment shown in FIG.19A, it will be appreciated that during startup of the system, exitvalve 1970 may be closed and bypass valve 1972 may be opened so that anamount of incoming fluid 1903 may be circulated through the system untilthe fluid reaches predetermined temperature T3 of about, for example,172° F. Once the system reaches its designed operating conditions, exitvalve 1970 may be opened and bypass valve 1972 may be closed. At thatpoint, control of the system is accomplished by temperature T3 at theoutlet of the primary heat exchanger 1910 and associated controlledvalve 1952 and liquid level control 1960 and its associated valve 1964.

The system 1900 functions as a chemical-free purification system forhighly contaminated industrial fluids, such as raw water intended to beused as frac water. The system 1900 effectively removes/kills bacterialcontaminates, free oxygen and the majority of grease and oils. Itvirtually eliminates the need for massive quantities of expensive andtoxic biocides and oxygen scavengers.

Field testing of a prototype has demonstrated results of effectivelyreducing total live bacterial cell count from contaminated water at369,100 cells per ML to under 500 cells per ML, without using chemicaltreatment agents; reducing dissolved oxygen from 12 PPM to under 1.5PPM; and reducing grease and oils from 831 mg/ml to 2.4 mg/ml, andincinerates hydrocarbons in the process.

The system 1900 can be designed to heat frac fluids 20° F. at 12 bbl perminute. Higher heating rates are achievable, up to about 60° F., but atlower flow rates. The countercurrent, cold and heated fluid flows allowthe system to heat fluids at high temperatures for bacterial eliminationand then transfer the heat to the incoming cold fluid. The systemfunctions economically and is cross-exchanged for energy efficiency.Total energy cost for natural gas and grid power rate is estimated atapproximately $0.05/bbl. Using generator power and propane, costs tooperate are approximately $0.15 per bbl. Further, up to three systemscan be operated in parallel from a single control station by a singleoperator.

The system 1900 of FIG. 19A utilizes a closed loop, direct-fired hotwater boiler system, isolating worked fluids from the high temperatureboiler tubes that are exposed to the direct flames. Waters to beprocessed are heated by closed loop titanium Tranter® plate and frameheat exchanger. It is presently desired to keep fluid temperatures belowthe scale forming temperatures of most contaminated waters to beprocessed. After waters have been processed through the heat exchanger,they are then circulated through an orifice into a high vacuum flashtank. In the flash tank, the superheated waters flash off steam, whichis condensed in a plate and frame heat exchanger cooled bycross-exchange with the cold, raw, contaminated water entering thesystem, thus recovering the majority of the treatment energy. Under thetemperature, vacuum, and during the retention time encountered in theflash tank phase, the water is pasteurized and degassed, killing theorganisms by heat and vacuum, and removing oxygen and volatilehydrocarbons. All of the vapors not condensed may be passed to thedirect-fired boiler's firebox and are incinerated and harmlesslydischarged into the atmosphere. The system 1900 facilitates de-isaeration of fluid, e.g., O₂ removal at 175° F. and 21 to 23″ Hg vacuum.

The pasteurizing system 1900 illustrated in FIG. 19B is similar to thesystem 1900 illustrated in FIG. 19A, and except as noted below, thedescription for FIG. 19A applies generally to FIG. 19B. In the system1900 shown in FIG. 19B, the incoming contaminated fluid is pumpedthrough the steam condenser 1996 to condense the steam that flashes outof tank 1928. The condensate is received in vacuum receiver 1968. Thecontaminated fluid exits the condenser at about 94° F. and enterspreheater 1998, which transfer heat from the blowdown from flash tank193 to the contaminated fluid. The contaminated fluid exits thepreheater at about 159° F., which can be controlled by valve 1994, andenters the primary heat exchanger 1910 to raise the temperature of thecontaminated fluid to about 169° F. The heated contaminated fluid isflashed into tank 1928 where it resides at about 165° F. for a perioddetermined by valve 1992 sufficient to eliminate or reduce objectionableorganisms. The system 1900 of FIG. 19B is configured to generated 2,000lbs of steam at about 165° F. Thus, FIGS. 19A and 19B illustrate anotheraspect of the present inventions for heating and manipulating fluids.

FIGS. 20A and 20B illustrate yet other embodiments of one or more of theinventions disclosed herein. More specifically, FIG. 20A shows system2000 that may be used to heat fluid 2011, such as industrial or oilfield fluids; and to pump or inject such fluids under high pressure. Thesystem 2000 may comprise a closed-loop heating subsystem 2003 having a600 kw diesel genset 2001 comprising a diesel engine 2002, which ispreferably a 600 horsepower, Tier III, turbocharged, diesel enginecoupled to an electric generator 2005 supplying, for example, 480 volt,3-phase electricity 2007 The heating subsystem 2003 may also comprise aworking fluid tank 2010, an electric boiler 2009, and a primary heatexchanger 2006, all plumbed in closed-loop fluid communication; anengine water jacket heat exchanger 2015; and an engine exhaust gas heatexchanger 2016. The fluid to be heated 2011 is plumbed through each ofthe heat exchangers as shown in FIG. 20A, such that the fluid may exitthe primary heat exchanger 2006 at the desired or predeterminedtemperature. The system 2000 also may include a high pressure pump 2050,such as, but not limited to a Gardner Denver 200 Hp kill pump, or othertype of pump, including other variable speed, plunger style kill pumps.

The engine water jacket heat exchanger 2015 may be a fluid-to-fluid heatexchanger, such as a plate and frame heat exchanger. One flow path iscoupled to the diesel engine 2002 water jacket and engine radiator 2034.A second flow path couples the diesel engine 2002 water jacket and thewater jacket heat exchanger 2015. It will be appreciated, as shown, thatcontrollable (or manual) valves may be placed in the flow paths to forcethe water jacket coolant to flow solely through the engine radiator2034, or to also flow through the water jacket heat exchanger 2015. Itwill be understood that when coolant flows through the heat exchanger2015, heat may be transferred to the incoming fluid 2011. Alternately,when the heat exchanger 2015, is bypassed, the incoming fluid 2011 willnot be pre-heated by heat exchanger 2015.

The engine exhaust 2013 may also be used as a source of heat to preheator heat incoming fluid 2011. As shown in FIG. 20A, controllable (ormanual) valves may direct the engine exhaust to a conventional muffleror muffler/catalyst exhaust system 2017 or to an air (i.e., exhaustgas)-to-fluid heat exchanger 2016.

Primary heating of the fluid 2011 occurs in primary heat exchanger 2006.Electricity 2007 from the generator 2005 powers the boiler 2009. Theboiler 2009 heats the working fluid in the heating subsystem to apredetermined temperature T1 and then directs the heated fluid to afluid-to-fluid heat exchanger 2006, such as a plate and frame heatexchanger, to heat the incoming fluid 2011. Cooled working fluid exitsthe heat exchanger 2006 and flows to a tank 2010. For the embodiment ofFIG. 20A, the tank 2010 is un-pressurized and vented to atmosphere,thereby operating at atmospheric conditions. The boiler working fluid ispreferably a glycol and water mixture and is drawn from the tank 2010 bypump 2008 and pumped back to boiler 2009.

It will now be appreciated that system 2000 may be used to circulate afluid 2052 into a tank (not shown) by running the diesel engine 2002 andgenerator 2005 to power incoming fluid pump 2019. Circulation of fluid2011 can include, optionally, heating of the fluid as described above.Additionally, system 2000 can be used to inject high-pressure fluid 2054into a well or other structure. High pressure injection of fluid 2054can include, optionally, heating of the fluid as described above. FIG.20B illustrates the system 2000 of FIG. 20A disposed on a conventionaltrailer of an 18 wheel tractor/trailer combination.

FIGS. 21A and 21B illustrate embodiments of the present inventions thatare useful to recover, recycle and/or dispose of water-containingindustrial fluids, such as, but not limited to, produced water orflowback water, by vacuum evaporation, de-aeration and/orpasteurization. It is contemplated that a system, such as described andshown in FIGS. 21A and 21B, can process about 13,600 barrels/day offluid, assuming the fluid is about 60,000 ppm TDS (predominately NaCl).

As illustrated in FIGS. 21A and 21B, system 2100 may be modular innature and construction to allow adjustability in capacity and toincrease transportability. For example, and without limitation, thesystem 2100 may comprise multiple, such as six, evaporation systems2110. In FIG. 21A, any of the evaporation systems illustrated in FIGS. 7through 12B may be used. Preferably, the embodiment of FIG. 21A utilizesan evaporation system 2110 such as described and illustrated in FIG.12A, including evaporation towers 2112. Preferably, the embodiment ofFIG. 21 B uses a multiple-effect evaporator system 2110 such asdescribed and illustrated in FIG. 12B. By combining multiple evaporatorsystems 2110 in this manner, my inventions can be scaled to a particularjob based on the amount of fluid to be treated, the location of the joband other such factors.

It will be seen from FIGS. 21A and 21B that contaminated fluid 2102,such as produced water may enter the modular system 2100 at a firstprocess point 2104, which may include hydrocyclones, oil skimmers,filters and other devices configured to remove particulate and othermacro contaminants from the fluid. Solid and/or particulates removedfrom the fluid may be passed to a landfill or otherwise properlydisposed of. Any oil recovered from the fluid 2102 may be commercializedor disposed of as allowed or desired. A portion 2106 of the fluid 2102may then be passed to the evaporation systems 2110 previously describedto remove and/or disposed of, through evaporation, a desired portion ofthe fluid 2102. As described for the evaporation systems illustrated inFIGS. 7-12B, in the case of produced water, the evaporation systems 2110will produce a concentrated fluid 2114, such as brine or 10 lb brine,which may be sold or disposed of as desired and/or allowed.

In addition, as described for the evaporation systems illustrated inFIGS. 7-12B, the evaporation systems 2110 will produce distilled wateror condensate 2116, which may be sold or disposed of or used as desiredand/or allowed. Use of condensate 2116 by process 2100 will be describedbelow.

Another portion 2108 of the water 2102 may be passed to a pasteurizationsystem 2120, such as any one of the systems described and illustrated inFIGS. 19A and 19B. Once the fluid 2102 has been pasteurized, it may beblended with condensate 2116, as desired or needed, to produce fracwater for use or sale.

Thus, the systems 2100 illustrated in FIGS. 21A and 21B may utilizevarious aspects of my inventions disclosed and taught herein to disposeof fluid by evaporation; to generate condensate for use or sale; topasteurize fluid for use or sale; and to reduce the amount of remainingfluid or solids that need to be disposed of.

My inventions have been described in the context of preferred and otherembodiments and not every possible embodiment of the invention has beendescribed. A person of skill in this art having the benefit of thisdisclosure will now be able to mix and match various aspects of theembodiments described herein to accomplish a particular task. A personof skill will also be able to take the teachings of this disclosure andrearrange components within an embodiment or take components from otherembodiments to create new embodiments, all without departing form thespirit of my inventions or the scope of the appended claims. Forexample, and without limitation, a person of skill having benefit ofthis disclosure will appreciate and understand that any of the heatingsubsystems described and illustrated in FIGS. 1 through 6B may be usedwith any of the fluid evaporation systems or subsystems described andillustrated in FIGS. 7 through 12C; or with any of the fluidconcentration systems or subsystems described and illustrated in FIGS.13 through 16; or with any of the fluid fractioning systems orsubsystems described and illustrated in FIGS. 17 and 18; or with any ofthe fluid pasteurizing systems or subsystems described and illustratedin FIGS. 19A and 19B; any of the fluid systems or subsystems describedand illustrated in FIGS. 20A through 21B. Those person of skill havingbenefit of this disclosure will be encouraged to combine these varioussystems and subsystems to achieve the functional and operational targetsfor each implementation of my inventions. In addition, various of thesesystems and subsystems, such as, but not limited to, when used toproduce frac water from produced water, may benefit from conventionalfiltration techniques including mechanical filtration and/or reverseosmosis filtration. While a developer's efforts to select and combinethese various systems and subsystems might be complex andtime-consuming, such efforts would be, nevertheless, a normalundertaking for those of ordinary skill in the art having benefit ofthis disclosure.

It will be appreciated that the fluid transporting conduits used withembodiments of the present invention may comprise piping, tubing andother fluid communications means of conventional and unconventionaldesign and material. For most systems described herein it is preferredthat the piping material be carbon steel, when possible. Of course, theoperating environment may dictate the material that is used. Thecirculation pumps may be of any conventional or unconventional design,but for the produced water embodiment described herein, it is preferredthat the pumps be hydraulic, pneumatic, electrical or direct drive(e.g., engine PTO) centrifugal pumps. Metering or positive displacementpumps, such as, but not limited to, Moyno pumps, may be used at variouslocations throughout the system as desired or required by the specificimplementation. Detection or determination of system properties orcharacteristics, such as, but not limited to, pressure, temperature,density, flow rate, or Total Dissolved Solids, may be acquired throughconventional instrumentation and data acquisition techniques, includingmanual techniques, as are well known to those of skill in the art.

Modifications and alterations to the described embodiments are nowreadily available and apparent to those of skill in the art. Thedisclosed and undisclosed embodiments are not intended to limit orrestrict the scope or applicability of the inventions conceived of, butrather, in conformity with the patent laws, I intend to protect all suchmodifications and improvements to the full extent that such falls withinthe scope or range of equivalents of the following claims. If a word orphrase used in a claim does not appear in reference to a figure herein,and such word or phrase has no specialized meaning in the relevant art,then any such word should be construed according to its ordinary andcustomary meaning and any such phrase should be construed according tothe ordinary and customary meaning of each word in the phrase.

What is claimed is:
 1. A method of concentrating a fluid, comprising:providing a closed-loop heating subsystem comprising a thermal energydevice, a fluid circulation pump, a first path through a fluid-to-fluidheat exchanger, all configured to heat and circulate a first fluid toless than its atmospheric boiling point; providing a fluid concentratingsubsystem comprising a flash tank, a second path through thefluid-to-fluid heat exchanger and a condensing heat exchanger; pumping asecond fluid through the second path in the fluid-to-fluid heatexchanger; transferring heat from the first fluid to the second fluid inthe fluid-to-fluid heat exchanger; flashing the second fluid into itsliquid and vapor phases in the flash tank is to evaporate at least aportion of water from the second fluid; drawing the second fluid vaporfrom the flash tank into the condensing heat exchanger to condense thevapor to liquid by transferring heat from the vapor; and removing aportion of the liquid phase from the flash tank as concentrated fluidwhen a pre-determined property of the liquid phase is reached.
 2. Themethod of claim 1, wherein the thermal energy device is selected fromthe group consisting of: a direct-fired, hydrocarbon-fueled boiler; arotary heating device driven by an internal combustion engine; and aDiesel-Electric generator set powering an electric boiler.
 3. The methodof claim 2, further comprising: operating the flash tank at less thanatmospheric pressure.
 4. The method of claim 2, further comprising:preheating the second fluid by transferring heat from the concentratedfluid.
 5. The method of claim 2, wherein the condensing heat exchangeris a fluid-to-fluid condensing heat exchanger and further comprising:providing a retention area holding a quantity of the second fluid;extracting a portion of the second fluid from the retention area to bepumped to the fluid-to-fluid heat exchanger; and using another portionof the second fluid in the retention area to cool the vapor phase in thecondensing heat exchanger.
 6. The method of claim 2, comprisingoperating the condensing heat exchanger at less than atmospheric ispressure.
 7. The method of claim 2, wherein the second fluid is dilutedcompletion fluid and the concentrated fluid is a completion fluid. 8.The method of claim 2, wherein the second fluid is produced water andthe concentrated fluid is a concentrated brine solution.
 9. The methodof claim 2, further comprising: withdrawing a portion of the liquidphase from the flash tank; determining a property of the withdrawnliquid phase; and mixing the withdrawn liquid phase with the incomingsecond fluid.
 10. The method of claim 9, further comprising: using theproperty determined from the withdrawn liquid to control the removal ofthe portion of the liquid phase from the flash as concentrated fluid.11. The method of claim 2, wherein the condensing heat exchanger is anair-to-fluid condensing heat exchanger.
 12. A fluid concentratingsystem, comprising: a closed-loop heating subsystem comprising a thermalenergy device, a fluid circulation pump, a first path through afluid-to-fluid heat exchanger, all configured to heat and circulate afirst fluid to less than its atmospheric boiling point; a fluidconcentrating subsystem comprising: a second path through thefluid-to-fluid heat exchanger; a pump for pumping a second fluid throughthe second path in the fluid-to-fluid heat exchanger to transfer heatfrom the first fluid to the second fluid in the fluid-to-fluid heatexchanger; a flash tank having an orifice through which the heatedsecond fluid is flashed into its liquid and vapor phases to evaporate atleast a portion of water from the second fluid; a condensing heatexchanger to condense vapor withdrawn from the flash tank to liquid bytransferring heat from the vapor; and an extraction system for removinga portion of the liquid phase from the flash tank as concentrated fluidwhen a pre-determined property of the liquid phase is reached.
 13. Thesystem of claim 12, wherein the thermal energy device is selected fromthe group consisting of: a direct-fired, hydrocarbon-fueled boiler; arotary heating device driven by an internal combustion engine; and anDiesel-Electric generator set powering an electric boiler.
 14. Thesystem of claim 13, further comprising: A vacuum system to operate theflash tank at less than atmospheric pressure.
 15. The system of claim13, further comprising: a fluid-to-fluid preheating heat exchanger forpreheating the second fluid by transferring heat from the extractedconcentrated fluid to the incoming second fluid.
 16. The system of claim13, further comprising: a retention area holding a quantity of thesecond fluid; and wherein the condensing heat exchanger is afluid-to-fluid condensing heat exchanger for transferring heat from thevapor to portion of the second fluid from the retention area.
 17. Thesystem of claim 13, further comprising a vacuum system for operating thecondensing heat exchanger at less than atmospheric pressure.
 18. Thesystem of claim 13, wherein the second fluid is diluted completion fluidand the concentrated fluid is a completion fluid.
 19. The system ofclaim 13, wherein the second fluid is produced water and theconcentrated fluid is a concentrated brine solution.
 20. The system ofclaim 13, further comprising: a liquid phase flow path between theliquid phase in the flash tank and a second fluid inlet to thefluid-to-fluid heat exchanger; a device for determining a property ofthe liquid phase in the liquid phase flow path.
 21. The system of claim20, further comprising: a control signal from the property-determiningdevice to the extraction pump to control the removal of the portion ofthe liquid phase from the flash tank as concentrated fluid when thedetermined property reaches a desired value.
 22. The system of claim 13,wherein the condensing heat exchanger is an air-to-fluid condensing heatexchanger.